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AMFITEATAR - Naucni portal

Nov 27th
Početna strana arrow Rubrike arrow Sci-Tech arrow Upgrade your iMac 20", 24", 21.5", 27" aluminum 2007-2011 to 1.5, 2.0, 3TB Hard Drive - DIY Guide
Upgrade your iMac 20", 24", 21.5", 27" aluminum 2007-2011 to 1.5, 2.0, 3TB Hard Drive - DIY Guide E-mail

This is your ORIGINAL iMac hard drive upgrade guide, created and updated since 2007 (and still current in 2014) with over 800,000 unique views! Get your questions answered and help you need in the comments section below.  Smile

~ iMac Optical, CPU, GPU upgrade guides coming soon! ~



Mac Logo
The following guide provides step by step instructions on how you can disassemble and upgrade your Apple iMac 20", iMac 21.5", iMac 24"  and iMac 27" (aluminum, models 2007, 2008, 2009, 2010 and 2011) to 1 TB, 1.5 TB, 2TB or even 3TB (terabyte) hard drive and 4GB - 6GB RAM (iMac 2007, 2008), 8 GB RAM (iMac early 2009) and 16 GB RAM (late 2009, 2010 and 2011) - all by yourself, and save some serious money (I've personally saved over US $1,000 upgrading my iMac by myself), however you will need some background in electronics and relevant experience to make it happen... 


You WILL need some basic technical knowledge to upgrade your iMac hard drive by yourself - upgrading hard drive is not user serviceable part and it might void your Apple warranty. Therefore, I cannot be responsible for any damages or losses you'll potentially incur from following this guide - proceed at your own risk!

Desire for the Top of the Line iMac Aluminum (2007, 2008, 2009, 2010, 2011) for Least the Money $$

Copyright 2007-2014 Amfiteatar Portal. All rights reserved.

iMac 2007, 2008, 2009, 2010 and 2011 memory and hard drive upgrade original guide

It all started in Oct-2007 - I wanted a brand new iMac 24" Aluminum with the 2.8 GHz Core2Duo Extreme CPU, max. memory (4 GB) and lots of internal hard drive capacity (1 TB - at the time), however ordering a custom built model with such features through Apple's web site was costing an arm and a leg (US $3,449 to be exact in Nov-2007), so I've decided to take a DIY approach, also taking into consideration my electronics background.

I've ended up ordering iMac 24" AL (2007) with 1 GB RAM, 320 GB HDD and 2.8 GHz Core2Duo Extreme CPU (approx. US $2,049 - the Extreme CPU was the only custom upgrade to my order). Then I've ordered 2 modules x 2 GB RAM (total 4 GB, costing me approx. US $140) and 1 TB hard drive (costing me approx US $310). My total cost for the machine and parts was ~ US $2,499 - saving approx. US $950 than ordering machine with such configuration through Apple (US $3,499 retail). In addition, after the upgrade I've sold the remaining parts - 1 GB RAM module and 320 GB hard drive through eBay, hence my saving on my new iMac reached over US $ 1,000 US. Cool, eh?

RAM upgrade was a breeze, just opened up the memory bay slot, plugged in the new modules and closed it up! However, upgrading hard drive proved to be somewhat challenging, hence I wanted to share my experience with the Mac community. Good thing is that I was taking photos as I've went along with the upgrade. The result is the following upgrade guide.

Danny, 5. Nov. 2007. 

Updated message: Since my original experience, I've replaced my iMac 2007 with a newer iMac 2008 and have had numerous iMac upgrade experience with all three models 2007, 2008 and 2009. This guide applies to all three models as all three models are internally 98% the same. 

I would like to thank all readers for their support and over 140 useful reader comments below. 

Danny, Apr. 2009.

Updated message: It is now possible to upgrade your iMac to 2TB hard drive using the guide below! It is now possible to upgrade iMacs 2007 and 2008 to 6GB RAM in total (although the  official specifications are 4GB max) - this is being updated in the appropriate section below and I have also added an iMac RAM memory upgrade table to help you out in various scenarios.  

I would like to thank all readers for their support and over 270 useful comments to this article!

Updated message: It is now possible to upgrade your iMac i5 and i7 models using the guide below! However, Apple made some changes and it is now using hard drive's internal temperature sensors in order to control the cooling fan speeds and not all hard drives are compatible. In order to upgrade your iMac i5 and i7 (21.5 and 27 inch) models you will need to use Western Digital hard drives only - these are being used by Apple and are compatible with temperature reading mechanisms in iMacs i5 and i7.

Danny, Dec. 2009. 

Over 370 user comments! Keep the questions and comments going!

I would like to thank all readers for their continuous support!

Danny, Oct. 2010.

Update: It is now possible to upgrade all of your iMac 2007-2011 with 3TB hard drive. For iMac 2007-2008 you can choose any hard drive you like and for iMac 2009-2011 you should use Western Digital drives only (due to the temperature sensor issue compatible with WD line of drives).

Danny, Aug. 2011

Update: As technology advances now we have 4TB hard drives on the market  - your iMac will be truly on "steroids" with this upgrade :) This manual is still applicable for 4TB hard drive upgrades.

Thank you on your support and 500 user comments :)

 Danny, Feb. 2012

Cleanded up and updated the article based on all of your experiences and feedback! Thank you all! :)

 Danny, Aug. 2013

Thank you on your support keeping this topic alive for 7 years! This guide has helped thousands of people upgrade and extend the life of their iMacs :)

Keep the questions and comments going! 

 Danny, Aug. 2014

Article revisions: Jan, May, Oct, 2008; Jan, Mar, Apr, July, Sep; Dec, 2009; Mar, Oct, 2010. Apr, 2011., Aug 2011; Feb 2012, Aug 2012, Mar 2013, Aug 2013, Jan, 2014, May 2014



Apple Online Store
Great deals from Apple Store Online  

What You'll Need

1) Apple iMac 20" or iMac 24" Aluminum

(2007 models - MA876LL, MA877LL or MA878LL or 2008 models - MB323LL, MB324LL, MB325LL, as well as 2009 models MB417LL/A, MB418LL/A, MB419LL/A, MB420LL/A): If you purchase your iMac online you can save additionally on the sales tax, and most of the retailers offer some sort of rebate as well. The configuration you're looking for is with 250 GB hard drive for 20" model or 320 GB hard drive for 24" model (the lowest drive capacity available, because you'll anyhow upgrade the hard drive to 1 TB, 1.5 TB, 2.0 TB or 3.0 TB.

You might choose from one of the following iMac 20" and iMac 24" aluminum 2008 and 2009 models you'd like to upgrade with 1 TB, 1.5 TB or 2 TB hard drive:

20in iMac 2008
24in iMac 2008
20in iMac 2009
24in iMac 2009

Save up to $100 on a New Mac and Printer! (Apple Store specials)


Also make sure to check out Apple's refurbished deals, from time to time (you just need to keep looking as offers change weekly) they'll have iMac AL 20" and 24" at bargain prices (e.g. iMac AL 20" for about US $850 and iMac AL 24" for about US $1200 - info spring 2009):


Apple Store Save big on Apple-certified refurbished Macs (Apple Store specials)


2) 1 TB, 1.5 TB, 2 TB or 3 TB (terabyte) SATA II or III, 3.5" hard drive

In my original iMac 2007 upgrade in Nov-2007 I've purchased a Hitachi 1 TB drive A7K1000, primarily because of 32 MB cache memory, SATA II interface having 3 Gbit/sec. throughput, and also due to its long-lasting life and reliability - Hitachi extending 5 year warranty and advertising 1.2 million hours average time before failure (choose a good drive - don't you just hate when the drive dies on you and you lose all your data!). I've owned this hard drive for more than a year and I was really happy with it. The average running temperature was about 57C (135F), which is within Hitachi's standard operating parameters - up to 60C - 140F.

Hard drives Apple installs in iMacs are Western Digital, you are also well set purchasing one of WD's 1 TB drives.

Update 1: Some of our readers have reported that their 1 TB WD Black and 1 TB Seagate hard drives are not as quiet as they've hoped for.

Update 2: Since my original upgrade, I've replaced my machine with iMac 2008 and I have upgraded my new machine with Seagate Barracuda 1.5 TB drive (64 MB cache). I'm very satisfied with this drive as well (owning it for several months now) - it has a great performance, it is very quiet and the average running temperature is about 58C (136F).

Update 3: Some of our readers have reported that Seagate 1.5 TB is very quiet in their machines as well.

Update 4: It is now possible to upgrade your iMac to 2 TB hard drive with Seagate Barracuda 2.0 TB or WD Green 2.0 TB ! (July-2009)

Update 5: It is now possible to upgrade your iMac to 3 TB hard drive with Western Digital 3TB (64Mb cache) (April 2011).


The appropriate 1 TB, 1.5 TB, 2 TB and 3 TB SATA hard drives going into your iMac are the following: 

Highly Recommended
Best Buy for your iMac upgrade is Seagate 1.5 TB drive
Cost vs Storage Capacity, Performance and Noise


NEW - 3.0 TB or 2.0 TB hard drive upgrade - you can now upgrade your iMac to 3.0 TB or 2.0 TB hard drive following the procedure described in this article!


The 3.0 TB hard drive you need is Western Digital 3TB (ST1500DL003).

The 2.0 TB hard drive you need is Seagate Barracuda 2TB (ST32000542AS) for the best peformance or WD Green 2.0 TB also having a good performance, but rather less expensive at this point in time. The 3.0TB (July-2009).

If the upgrade cost is you major concern, you also might consider going with a really affordable Seagate 1.5 TB (ST1500DL003 or ST31500341AS) - the best buy for your money performance vs noise!

Update 1: Our readers have sent us confirmations on successful iMac aluminum upgrade to Seagate 1.5 GB hard drive -- check out the comments at the end of the page (thank you Doug, Oct-2008)!

Update 2: I've upgraded my new iMac 2008 with 1.5 TB hard drive in Dec-2008 and all went smoothly!

Update 3: I've upgraded my friend's iMac 2009 wtih 1.5 TB hard drive in Mar-2009, layout of the computer inside is identical with the previous models.

Update 4:  After a long experience in upgrading iMacs (2007, 2008, 2009, and 2010) with new hard drives, it seems that 1.5 TB Seagate Barracuda or WD Green 2.0 TB is currently the best buy for your money vs storage space, performance and noise! (update Aug-2011)

Your choice of recommended 3 TB drives is as follows: 

Top 3TB
Best value
for 3TB

Your choice of recommended 2 TB drives is as follows: 

Top 2TB
Best value
for 2TB

Your choice of recommended 1 TB drives is as follows: 

Although 1.5 TB and 2.0 TB drives provide a better value for the money, here are some 1 TB hard drive recommendations just in case you have a really old machine (e.g. iMac white):

WD Caviar Black 1 TB or WD Green 1 TB


Once You Know, You Newegg Newegg.com specials on hard drives, internal and external
(also a great source for an external hard drive for your Time Machine backups)

3) Torx screwdrivers: You'll need several specialized TORX screwdrivers, size T6 and T8 (these screwdrivers are the same type used to work with mobile phones).

Six-Piece Mini Torx Screwdriver Set


Torx screwdriversTorx screwdrivers


4) Kitchen \ bathroom hook suction cups: In order to open your iMac AL, you'll need to take the glass cover off the display. The glass cover is held in place only by several magnets -- in order to remove it you'll need a specialized suction cup handle: 

Glass Handle Tool


However if you don't own such a fancy tool, several kitchen \ bathroom hook suction cups will do the trick instead (as in my case :) Just make sure they're larger cups - at least 1 to 2 inches in diameter.

Suction Cups with Handle


Upgrade Guide - Step-by-Step Instructions with Photos

Applicable to iMac 2007, 2008 and 2009 models (both 20 and 24 inch):
- iMac 2007 models MA876LL/A, MA877LL/A, MA878LL/A
- iMac 2008 models MB323LL/A, MB324LL/A, MB325LL/A
- iMac 2009 models MB417LL/A, MB418LL/A, MB419LL/A, MB420LL/A


Step 1 

Take a good look at your iMac AL - no screws (besides the memory upgrade slot) to be seen - how neat. :))))

In order to open your iMac, you will need to lift up the protective glass covering your display. The glass is held by several magnets only, so you just need to lift it up. Naturally you won't be doing this with a screwdriver beneath the glass as you will damage the frame for sure. You need suction cups to lift up the glass.

If you don't have specialized suction handle tools, using kitchen \ bathroom hook cups will do just fine. You will need about 4-6 of these, 1 to 2 inches in diameter.

Place the suction cups as shown on the photos. You might want to use a rubber string to tie up all suction cups (as shown on the photo) in order to have a grip at all suction cups simultaneously (otherwise you can try lifting up the suction cups with your bare hands ;).

Just LIFT UP the glass with the suction cups applying some moderate force. Make sure you do it carefully, as while pulling you might damage the glass!

Update 1 Some of our readers have managed to get the glass off using only two larger suction cups placed at the two opposite corners of the glass (e.g. upper right and lower left corner), and pulling with hands only (please check out the comments at the end of the page).


Once you lift up the glass, put it aside on a soft cloth. Finally we can see some screws in the frame! Use your Torx screwdrivers to take out all screws within the frame. Once you're done, lift up the upper side of the frame only, but carefully, as in the upper mid section (behind the integrated iSight camera), there will be a wire you need to disconnect (as shown in photos).

Update 2: One of our readers reminds there are various length screws you will be taking out - what he suggests is using a piece of 8.5 x 11 (or A4) paper and taping the screws with scotch tape on the paper in the proper location such that it would remind you as where do they go back (thank you Doug)!

Update 3: Some readers have reported they've managed to make the upgrade without disconnecting the iSight cable - leave it plugged in and just flip over the front panel at your desk (thank you Claudio).


Step 2 

Now make sure you take off the bracket from the memory slot at the bottom of the frame. If you don't do this, you won't be able to take off the frame.


Once you've put the memory slot bracket away, you may lift up the display frame entirely and set it aside.


Step 3

At this point we've unleashed the inside of your iMac AL - I truly admire Apple's compact design :) The next thing we need to do is to detach iMac's gorgeous display. Make sure you do this with utmost patience as you don't want to be responsible for any dead pixels in the process!

The display is attached with three connectors. The first two you can find on the left and the right hand side of the bottom of the motherboard. Let's start with the right-hand side connector first -- this connector is locked in with a screw - thus you need to take it off and pull out the connector. Now we move to the left-hand side connector - just unplug it carefully. You might want to use a precision screwdriver to help you out in the process. 

Update: One of our readers managed to upgrade the hard drive without removing the display - althought I've found it to be a lot easier to swap the hard drive with the display off.



Step 4

The third connector attaching the display is located underneath the display, in the upper left corner of it. The next step is to lift up the display VERY carefully from its right hand side and up (as shown in the picture), and you need to detach the third cable - which is a power connector connecting it to the power board (smaller blue board shown in photos).

In my case, I had to take off the screw holding the power board in place first in order to be able to take off the connector. You might want a second pair of hands helping you with this step (holding the display in the air while you pull out the power connector beneath it)!

Update: One of our readers reminds there are two screws on the side of LCD you need to remove in this step in order to lift the screen (please read the comments section at the end of this page).


Once you detach display power connector, you are ready to entirely lift off the display and place it aside. Make sure you put the display on a soft and safe place, away from the tools and work area (you don't want to damage it)!


Step 5

Finally, we can see the hard drive placed in the middle upper section of iMac's aluminum back frame. In order to take out the hard drive, you must first take off the temperature sensor from the drive (as shown in photos). The temperature sensor looks like an ordinary transistor component. Make sure not to bend its pins as it may damage it!


Next, pull out the SATA and power connector from the hard drive (left hand side of the drive in my photos). 


Step 6

For this step you will need to apply a bit of force - you need to push down the plastic handle attached to the upper part of the hard drive - push down until it unlocks and lift up the drive. Alternatively, the handle is held up with two screws, so you might want to take these off and slide out the handle easily out of its place.


You can see at the photo that Apple has used Western Digital WD3200AAJS - 320 GB hard disk in its iMac aluminum.


Step 7

The hard drive side opposite to the plastic handle has two metal pins screwed in - holding the hard drive's bottom side within the frame. Take (unscrew) these pins from the original hard drive and put them onto the new hard drive. Also, move the plastic handle from the old hard drive onto the new one (held up by two screws only).



Step 8

Use the backward logic to put back the new hard disk in place, bottom side with pins going into the frame first, then you snap it into the place by pushing the upper side handle into the frame (as show in photos)



Step 9

Attach the hard disk temperature sensor at approximately the same place where it was on the old hard drive. Use some glue if necessary (in my case there was enough adhesive left on the sensor, so I've just pushed it onto the drive and it stuck). Make sure you put the protective sponge on the top (as it was on the original hard drive).


Plug in the SATA and power connector to the drive (left-hand side of the drive in my photos).  


Step 10

It's time to put back the display -- we'll use the reverse logic - you need to plug in the power connector first (left hand side of the display) into the blue power board). Then place back the display firmly in its place - as shown in the photo. You might want a second pair of hands helping you with this step.


Then attach the two remaining display connectors at the left and right hand side at the bottom of the system motherboard. 


Step 11

Put the aluminum front panel back into its place (starting with the bottom side first), making sure you connect the integrated iSight camera wire at the top before entirely closing up the frame.


Then put all the screws you've taken out back into their places within the frame. 

Update: Make sure the silver piece (the protective foam) around the RAM slot is tucked back in as putting back the front panel will be much smoother (thank you Vincent).


Step 12

Before putting the protective glass back onto the display, you might want to wipe it off and the display itself with a soft cloth (e.g. such are cloths used to clean reading glasses) in order to get rid of the dust particles that have fallen at the display in the mean time. Please take care of what kind of cloth you use - you don't want to unnecessarily scratch your display!


You are ready to put back the protective glass on top of your display. Use suction cups to handle the glass. Make sure you put it back carefully, as magnets will snap it into the place.


Step 13

Put back the protective bracket onto the bottom memory slot (upgrading your RAM is as easy as plugging in the new memory modules into the slots).


* Pleae note: if you are not going to be upgrading RAM memory on your iMac, please scroll down to the last Step #14 of this guide - installation of OS X (on a blank hard drive).

Upgrading the Memory (optional step)

Your iMac (2007, 2008 and early 2009) has two memory bays (slots) available. Newer iMacs with wide screens (late 2009, 2010 and 2010) have four memory bays (slots) available.

First, you need to determine how much memory you already have installed and if one or both memory bays are being used. You can identify this by clicking on the Apple logo (upper left corner), then by clicking on About This Mac.

About This Mac

in About This Mac window you can find out how much memory do you have installed in total, however we also need to know if only one or both memory bays have been used. In order to find this out, clik on More Info button at the bottom of the window.

About this Mac - more info

Selection of more info will display System Profiler window - in there click on the Memory menu option on the left hand side and you'll be able to see the capacity of individual memory sticks installed in your machine and if one or both memory bays are occupied.

iMac 2007 screenshot shows 667Mhz memory modules installed:

System Profiler - assessing the RAM upgrade options for your iMac

iMac 2009 screenshot shows 1066Mhz memory modules installed:

System Profiler iMac 2009

Usually Apple has shipped 2GB and 4GB configurations with both memory bays used (2 x 1GB memory sticks  or 2 x 2GB memory sticks - one in each slot).


Please note that:

  • iMac 2007 and 2008 models  (20" and 24") are upgradeable to 6GB max. RAM memory.
  • iMac early 2009 models (20" and 24") are upgradeable to 8GB max. RAM memory.
  • iMac 21.5" and 27" inch (late 2009, 2010, 2011) are upgradeable to 16GB max.


Memory Upgrade Options (iMac 2007, 2008, early 2009 - all 20" and 24" models)

(for late 2009, 2010 and 2011 models 21.5" and 27", please scroll down)

Depending on how much memory do you already have and which memory bays are used provides you with a number of upgrade options. For easy communication we've made the following table for your reference:

iMac 2007, 2008 and 2009 RAM upgrade table

If only one of your memory bays is used, you can choose an option to add another module in there, or completely discard the existing module installed and install two new ones. Several examples on how this can work out in your case:

  • if both of your memory bays have 1 GB memory modules installed (total of 2GB), in order to upgrade to 4GB, you will need to discard both of 1GB modules and install two new 2GB modules
  • if you only have a single memory module installed, let's say 2GB, you might add another 2GB module in unoccupied bay in order to get to 4GB. (2 modules of 2GB = 4GB)
  • maximum configuration for iMac 2007 and 2008 models is 6GB, in such case you need to use 2 memory modules - one 2GB and the other 4GB (1 module 2GB and 1 module 4GB = 6GB)
  • similarly, maximum configuration for iMac2009 model is 8GB, in such case you need to use 2 memory modules - both 4 GB (2 modules 4GB = 8GB)

If you need to discard your old memory module in order to free up a memory bay, you can always consider giving it to a friend, or selling on eBay.

(for choice of recommended memory modules, please scroll down)

Memory Upgrade Options (iMac late 2009, 2010, 2011 - all 21.5" and 27" models)

iMac 2009, 2010 and 2011 RAM upgrade table

Newer Mac models (late 2009, 2010 and 2011) have four (4) memory bays (slots) available (unlike their predecessor having only 2 memory bays).  Depending on how many memory slots you have used, there are quite a few combinations in terms of possible upgrades. Please reference the table above in order to determine your upgrade options and memory modules you need to add, or to replace. The highest capacity these machines can be upgraded to is 16GB of RAM - all four (4) memory bays (slots) populated with 4GB 1333Mhz PC-10600 SODIMM memory modules.

(for choice of recommended memory modules, please scroll down)

Choosing the appropriate memory modules for iMac 2007, 2008, 2009, 2010 and 2011

Did you know that all iMac models use laptop (and not desktop) type of memory modules (they're called SO-DIMM memory modules)? That same memory does not have to be Apple branded, and it is also used in PCs as well - the same exact memory chips, the same exact components. Having said that, there are quite of few inexpensive options for upgrading your iMac memory on the market.

Compared to Apple's branded memory, the memory modules recommended in this section are only a fraction of the cost and they work 100% guaranteed (also confirmed by many readers of this article).

- iMac 2007 - (20" and 24")

The appropriate memory modules going into iMac 20" and iMac 24" aluminum 2007 models are the following PC2-5300 modules (1 GB or 2 GB modules, DDR2, 667 MHz, SO-DIMM 200 pin, unbuffered):

RAM for iMac 20in, 24in 2007 models
2 GB module
(667 Mhz)
4 GB kit (2x2GB)
(667 Mhz)
4 GB single module
(667 Mhz)
  For 6 GB upgrade use one 2GB 667 Mhz module and one 4GB 667 Mhz module.

Althoug offical Apple specifications say that this model can be upgraded to 4 GB RAM in total, it is a well known fact in the Mac community that iMac 2007 can be upgraded to 6GB RAM in total (because it has the same Santa Rosa chipset used in iMacs supporting 8GB of RAM). Some Mac users have tried upgrading this model to 8 GB RAM, however it proved to be very unstable and the hardware just couldn't handle it. Upgrading to 6 GB is stable and works very well in these models.

In order to max out your iMac 2007 memory to 6 GB you will need one 2GB 667Mhz unbuffered so-dimm and one 4GB 667Mhz unbuffered so-dimm memory module complying to PC2-5300 specification (choose from the above).

- iMac 2008 -(20" and 24")

iMac models from the early 2008 use faster 800 Mhz memory PC2-6400 (compared to 667 Mhz modules used in 2007 iMacs). Although the above suggested 667 Mhz  modules for iMac 2007 will work in your iMac 2008 (provided both memory modules are 667Mhz) you should really look into getting the faster 800 Mhz memory - therefore the appropriate memory modules going into iMac 20" and iMac 24" aluminum 2008 models are the following (1 GB or 2 GB modules, DDR2, 800 MHz, SO-DIMM 200 pin, unbuffered):


RAM for iMac 20in, 24in 2008 models
2 GB module
(800 Mhz)
4 GB kit (2x2GB)
(800 Mhz)
4 GB single module
(800 Mhz)
  For 6 GB upgrade use one 2GB 800 Mhz module and one 4GB 800 Mhz module.

This model as well can be upgradd to 6 GB RAM in total.

In order to max out your iMac 2008 memory to 6 GB you will need one 2GB 800Mhz unbuffered so-dimm and one 4GB 800Mhz unbuffered so-dimm memory module complying to PC2-6400 specification (choose from the above).

- iMac early 2009 - (non-wide screen models 20" and 24")

iMac models from the early 2009 use newer DDR3 memory running at 1066 Mhz memory PC3-8500. Memory modules for iMac 2009 are not compatible with iMac 2007 or iMac 2008 models. iMac early 2009 (20" and 24" inch - non-wide screens) can be maxed out to 8GB RAM memory in total.

Therefore the appropriate memory modules going into iMac 20" and iMac 24" aluminum 2009 models are the following (2 GB or 4 GB modules, DDR3, 1066 MHz, SO-DIMM 204 pin, unbuffered):


RAM for iMac 20in, 24in early 2009 models
4 GB single module
(1066 Mhz)
4 GB kit (2 x 2GB)
(1066 Mhz)
8 GB kit (2 x 4GB)
(1066 Mhz)

iMac 2009 can be maxed out to 8 GB of RAM memory -- for which you will need two (2) 4GB memory modules 2x4GB 1066Mhz unbuffered so-dimm complying to PC3-8500 specification (choose from the above).

- iMac late 2009, 2010 and 2011 - (all wide screen models 21.5" and 27")

iMac models from the late 2009, 2010 and 2011, use even faster DDR3 memory running at 1333 Mhz memory PC3-10600. Unlike their predecessor, these iMac models have four (4) memory bays available and can be maxed out to 16GB of RAM memory.

Therefore the appropriate memory modules going into iMac 21.5" and iMac 27" wide-screen aluminum late 2009, 2010 and 2011 models are the following (2 GB or 4 GB modules, DDR3, 1333 MHz, SO-DIMM 204 pin, unbuffered):


RAM for iMac 21.5in, 27in late 2009, 2010, 2011 models
4 GB module
(1333 Mhz)
8 GB kit (2x4GB)
(1333 Mhz)
16 GB kit (4x4GB)
(1333 Mhz)
  For 16 GB upgrade use four (4) x 4GB 1333 Mhz modules .

iMac late 2009, 2010 and 2011 can be maxed out to 16 GB of RAM memory -- for which you will need four (4) memory modules 4GB 1333Mhz unbuffered so-dimm complying to PC3-10600 specification (choose from the above).

Mixing incompatible memory modules causes system instability

Please note that for iMacs 2007 and 2008 models you should not mix 667 Mhz and 800 Mhz modules - either your both memory modules should be 667 Mhz, or they should both be 800 Mhz, but do not combine 667 Mhz and 800 Mhz modules at the same time as you cannot have two memory modules working at different speeds simultaneously - your machine is likely to crash often or not boot at all!

iMac early 2009 uses only 1066 Mhz (DDR3) memory modules - these are not compatible with previous models (2007, 2008).

iMac late 2009, 2010 and 2011 uses 1333Mhz (DDR3) memory modules - these are not compatible with previous models (2007, 2008, early 2009)

You also want both modules from the same manufacturer with exactly the same specifications (specifically CAS - CL latency) - even if you install two memory modules from the same manufacturer with the correct Mhz speed, if they differ in CAS - CL latency your machine is likely act up! This is important to take into consideration if you already have an existing module and would like to add an additional module - make sure you get exactly the same module as the one you already have OR throw out the existing module (i.e. sell on eBay) and install both new modules of the same manufacturer and specification - in such case your iMac memory upgrade will be a 100% success!!!


Apple Welcomes you Back to School

Apple Online Store

Step 14 - install OS X

Finally, as you've just installed a blank hard drive, you need to install OS X operating system on your iMac. Please note that if you have Leopard upgrade DVD, you will need to install Tiger first, and then upgrade the system to Leopard.

Update: One of our readers mentions that you can install OS X from the upgrade DVD version without previously installing Tiger if you select Time Machine Backup, and then cancel it by going back - at that point the upgrade DVD will allow you to install OS X on a blank hard drive without prior OS installed.

On the other hand, if you have the full version of Leopard OS X, just go ahead and pop in the DVD, turn on your iMac and it will boot from the DVD - just follow the instructions on the screen to install the operating system.

Please note that once you are booted to OS X Leopard installation you will need to start the Disk Utility in order to partition and format your new 1TB, 1.5TB or 2TB hard drive.

You might also want to consult Leopard OS X installation guide from Apple.

Update: In order to transfer data from your old hard drive, you can place your old hard drive into USB external case, connect it to your iMac and start Utilitie, Migration Assistant. If you've used Time Machine for backups, you can also recover you data from Time Machine utilizing the Migration Assistant.

Once you install the OS X, in order to verify the hard disk installation you need to click on the Apple logo (upper left corner), About This Mac, More Info, then Serial-ATA (or simply start System Profiler application from the Utilities folder).


 In order to verify the amount of memory (RAM) installed, click on the Apple logo and select About This Mac.

About this Mac - 4 GB RAM



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Comments (543)Add Comment
written by Fernando Leiria, December 28, 2007
Obrigado e-amigo
Thanks a lot e-friend
Thank You
written by Rich, December 28, 2007
Thank you for taking the time to photograph and document your upgrade. Nicely done!
goooood !!
written by xplane93, December 28, 2007
Bigs thanks for this Doc and photos very utlils.
Very nice job!
written by Rene Larsen, December 29, 2007
As the title implies, very nice job! This is by far the best documentation available currently for changing out your hard drive in an Aluminum iMac and the photos are great. Thank you very much for taking the time to put all of this together in such a logical and professional manner. Cheers!
written by popeye cahn, December 30, 2007
Now I know what I'll be doing soon. Thanks for the excellent write up and detailed photos!
written by beosro, December 30, 2007
You're the man!
Totally Execellent Documentation
written by iMC, January 01, 2008
As with one of the user posted, this is by far the best documentation on how to upgrade your Intel iMac (Mid 2007) aluminum. I just bought one ( refurbished ) with 1GB RAM/250GB HDD, and I was wondering how am I going to upgrade the memory and the HDD. Through some searching at the Apple Discussions board, I found your documentation through one of the posts. Great job on this.

These Intel iMacs (Mid 2007) aluminum aren't as user-friendly as on the G5 iMac. Just unscrew 3 to 4 screws, pop the back cover and voila, there it is, all at your disposal. Looks like Apple doesn't want the end-user to tinker the inside....... smilies/sad.gif
A good idea
written by Opa, January 04, 2008
Thats really a good and needfull help for all Apple-Users.
And many thanks for all the detailed photos.
written by Tom Loki, January 04, 2008
Great work - thank you!!!!
written by moreliaV, January 05, 2008
A really helpful instruction....it works !!!!
About the Leopard upgrade DVD
written by Miguel Palma, January 06, 2008
I did the replacement of my drive with a 500GB samsung HD501LJ, but I used a putty knife to remove the glass in Step 1, I also found a trick to bypass the Leopard Upgrade DVD check (on a forum...), just select the option for Time machine restore on the menu and them click on goback, the button to proceed with normal installation will them be activated
Can you upgrade the cpu as well?
written by Madmac, January 07, 2008
Thanks for the post, even that I'm a PC technician, look a little difficult to do the hard drive upgrade, I mean it's a little too risky, including messing with the iSight camera, but well done.

I have 2 more questions though. Is the CPU upgradeable or it is soldered? In the 20" mac it is possible to use a terabyte hard drive? I ask this because in the Apple website in the upgrade option shows that you can only install a hard drive up to 500 GB.. maybe a BIOS locked option?

Once again thanks a lot for showing the light!
Backside of glass front?
written by DrFelix, January 07, 2008
First: Thanks for the excellent How- To, brought up another idea: I would like to exchange the whole front with an anti- reflex glass. Found a company who cuts the anti- reflex glass to fit my 24 inch iMac. Black bezel will be painted from the backside. Only problem: How to fix the new glass into the frame. I've yet to open up my iMac and thought someone could help me out: Are there magnets glued to the backside of the original glass? Or is the black paint of the bezel magnetized?

Thanks in advance,
Reply: Can you upgrade the cpu as well?
written by Danny, January 08, 2008

In terms of difficulty of the upgrade - it's very relative - the above guide sure makes it a lot easier. I'll quote an editor of the specialized French Mac site Bidouille saying that this upgrade is not too difficult - http://www.hardmac.com/news/2008-01-03/.

The new iMac aluminum 20" will take 1TB drives (the motherboard is the same as with 24" model) - although Apple doesn't sell 20" models with 1TB drives, thus you can go ahead and upgrade your iMac 20" to 1TB hard drive.

Unfortunately I believe it is not feasible to upgrade the CPU in iMac 2007 models above 2.8 Ghz - Apple's 2007 product line. The reason might not be in the actual upgrade (replacing the chip) but in the fact that Apple motherboard (BIOS issue) might not recognize the newer CPUs (for example 3.06 Ghz) in iMac 2007 models.

The only way to test this is through a trial and error - I don't have the time or motivation to do it at this time, perhaps some of the readers will try if newer 3.06 Ghz CPUs will work in iMac 2007?

On the other hand I believe iMac 2008 models will most likely have no trouble upgrading the CPU to 3.06 Ghz - as Apple uses the same motherboards for the entire product line (and there is a 3.06 Ghz product in 2008 line up).

What other drives (like 500GB) can be used...also, what about 17" iMac (white)? is it similarly opened?
written by Kevin, January 10, 2008
Thank you for this amazing guide!!! I'm excited to crack open my new iMac and upgrade the drive.

First, I'm not all that interested in the full 1TB drive upgrade so what drive type can be used for about 500GB?

Second, is this guide anywhere near how to open up the previous white iMacs (17, 20,, 24)? I have a 17" I'd like to upgrade, but I don't know how to take it apart.
Reply: Backside of glass front
written by Danny, January 11, 2008

That sounds like an interesting modification smilies/smiley.gif

I've zoomed up one of my photos were you can see the back of the glass.

The magnets are not located on the glass - they're embedded within the aluminum bezel. The back of the glass - around the borders - is applied with a metallic stripe. Also, please note several spike-looking guides helping fix the glass within the frame.

Hope the above helps. Please send us photos of your modification.

Reply: iMac white hard drive upgrade and 500 GB HDD recommendation
written by Danny, January 11, 2008

I believe a very good guide to open previous generation iMac white was written by John Wood.

In terms of what hard drive to choose for your iMac white (these could also be used in alu iMacs), I can recommend Western Digital Caviar 500 GB hard drive (SATA, 16 MB cache).

Good luck upgrading!

Sr. IT Consultant
written by Sijo, January 13, 2008

really helpfull. Thanks a TON !!!
Temperature sensor adhesive recommendation?
written by Ken, January 17, 2008
Will ordinary Elmer's Rubber Cement work well enough or can anyone recommend a better adhesive that can be used to adhere a temperature sensor to a new hard drive? A URL to an appropriate adhesive product would be appreciated.
This is just too cool info!
written by Gary Stamey, January 24, 2008
THANKS so much!
Amazing thank you
written by artske, February 09, 2008
I have been searching for this tutorial for a while now , I plan to do this upgrade very soon and will let you know how I get on, once again thank you for such an in depth tutorial smilies/wink.gif
written by Dave, February 16, 2008
did this. couple things of note: 1) suction cups are easy, use 4 - one at each corner. 2) make SURE you put all bezel screws in tight/flush (I missed one, cracked the glass, GRR, who knows what that will cost). 3) you can just unscrew the 2 screws holding the drive to the "handle" and then pop it out, transfer the two metal tabs, and put the new one in - much like doing one in a MacBook Pro. 4) be careful of the EMI shield (silver-ish fabric stuff) down by the RAM slots - and also, put the outer bezel back on BOTTOM FIRST - I had to take it on/off 3 times to get it right, all for the want of some silly small things. 5) If you do have that 2nd-set of hands (or good 2 yourself) you can do it without taking out the "blue board" or unplugging the LCD in the 3rd step - but don't crush wires on the left or stretch the power ones!
Temperature sensor adhesive recommendation? - 2nd try
written by Ken, February 19, 2008
Does anyone know if ordinary Elmer's Rubber Cement work well enough or can anyone recommend a better adhesive that can be used to adhere a temperature sensor to a new hard drive?
written by axel Pfister, February 23, 2008
Wow this is exactly the instruction i'm looking for. Is it different when i only want to put s second drive in my 24 imac.

On the glue issue I would not use elmers glue in a computer period.
written by James McDonald, February 27, 2008
On the glue issue I would not use elmers glue in a computer period.

You might try Deacon Weld it. On my cloth dryer the rubber sealer ring on the door started coming off about 5 years ago. I Glued it back on and it's still fine. I fugue sustained high temperature might be around 150 F in the dryer. The strength in 900 LBS / IN SQ.

It work well with plastics and metal. Handling time is 5-6 minutes. Time to set is 1.5 to 3 hours. You might want to affix the temperature sensor to the HD with a drop of super glue if you can't get the sensor to lie in the right spot. Two coatings is probably best. Do the second coating perhaps 70 minutes after the first.

Devcon Weld-It

Weld-It User Review - Video
Thank you so very much!
written by Eric, March 17, 2008
This information is awesome. I have been searching EVERYWHERE for the answer to crack this case open. What a genious design! Thank you for leading the way. This was so helpful.
written by Mac Newbie, May 09, 2008
Gutsy my man, very gutsy. I have attempted this procedure myself but had to relinquish my only b/c it was way over my head. Thanks to your procedures, photos and pre-cautions as to what obstacle we may encounter, I now feel confidence I can conquer this objective. My hat is off to you....
Onsite I.T
written by Scottuk, May 13, 2008
Great instructions, worked a treat , added a 1tb Wd HDD to my Imac.
Extra pair of hands make a big difference when unplugging the last four cables under the LCD.

Only small things I noticed were ..
1) I found it easier to leave Isight camera plugged in and just put the ali lid above the main case while working on the system.
2) As "..." said , when reassembling , make sure you tuck in all cables or the LCD wont sit properly , also put the top lid back on from the bottom up (I also had to try this several times before getting it right.

Also small set of long nose pliers come in useful for various sections of this install (but not essential).

To whoever wrote this guide , THANK YOU , it saved a lot of guesswork.

written by MrDrap, May 22, 2008
Thanks a lot for the Photo-manual, it helps me a lot, thanks a lot smilies/grin.gif smilies/grin.gif smilies/grin.gif smilies/grin.gif smilies/grin.gif smilies/grin.gif smilies/grin.gif smilies/grin.gif smilies/grin.gif smilies/grin.gif smilies/grin.gif smilies/grin.gif smilies/grin.gif smilies/grin.gif smilies/grin.gif smilies/grin.gif smilies/grin.gif
You made this a PIECE of CAKE
written by Bob, May 24, 2008
Took me all of about 30 minutes following your excellent tutorial to pop a 1TB into my iMAC 24 AL. Only thing that threw me was once the cover was removed there were 8 Torx Screws to be removed that held in the LCD frame before lifting it and detaching the 3 connectors.

I was surprised how easily the "glass" lifted. I used 2 x 2.5" suction hooks I found a Lowes. They have a hook that when turned down adds suction by puling up on the center of the suction cup. These are used for bathroom showers I think. Then the LCD come up so easy and was so light - plastic I'm pretty certain and I was expecting the weight of glass.

Anyway, hats off and Thank You.
extra screws?
written by Eric, June 15, 2008
I can't tell where the two longest screws go back in. Can someone help me out? The bezel is really loose and I'm afraid someone will be able to just pull it off one day. smilies/sad.gif
Reply: extra screws
written by Danny, June 15, 2008

All the screws holding the bezel are in front, around the frame and behind the glass - as shown in this photo. I remember those big screws going in the bezel's bottom part.

Good luck,

written by Claudio Dalla Vecchia, July 08, 2008
Hi all,

I just replaced the HD on my iMac AL 20", and this tutorial has been very useful. Just a few remarks:

1. it's not necessary to disconnect the iSight cable - just flip the frame over;

2. to remove the monitor one has to unscrew 8 more screws;

3. it doesn't matter which power cables you plug the monitor in;

4. I have a set of TORX T6-20 and didn't need the T4 at all - I mostly used T6 and T9;

5. when one installs Tiger, the HD is not found until it is partitioned with Disk Utils - I guess some HD are already formatted though.

Thanks a lot,
written by chris , July 17, 2008
i found the isight camera connection easy to remove and the bottom plug to the screen fairly easy the left and right i looked both seemed so taped up so i changed the hard with those 2 still attached. putting everything back no problem. These instructions are just what i needed perfect if i had paid apple to upgrade my hard drive would of cost the earth, its shame they cant include this in their manuel especially with what they cost.

Perfect just perfect......

imac 24" 3.06ghz, 500gb h/d, 2gb mem

upgraded to;


written by chris, July 17, 2008
just fantastic this is great for those that need this upgrade info if only apple could afford a few extra pages in the manuel.
written by david, July 26, 2008
Does anyone think the new velociraptor drives would be too hot to put in the IMAC?
written by Allenb, August 10, 2008
I really appreciate the time you took to make this info available. You did a great job in laying out what was involved. I have a 24??????? (May 0smilies/cool.gif and the hard drive failed. It????????s still under warranty but I????????m three plus hours from the nearest Apple service. With your info I????????ll be able to replace the drive myself (it????????s less expensive than the trip.) Thanks again
Seagate Barracuda 750GB for this iMac ?
written by Jseda, August 10, 2008
Which hard drive can you recommend for a Intel iMac 20" aluminun ?
Im thinking to put a Seagate Barracuda 7200.11 750GB Hard Drive - 7200RPM, 32MB, SATA-300.

I just saved $2,000
written by david, August 20, 2008
Wasn't sure I could do it - especially after reading about the person who broke their screen - but thanks to your detailed directions, I did. (And because mine is only 20," I was able to do it myself.)
Thanks for sharing your knowledge!
Great documentation
written by Michael, August 28, 2008
Whatever the Mac community may lack in numbers it sure makes up in quality
written by Roberto, September 05, 2008
You contributed to human kind progress!!!

smilies/wink.gif smilies/wink.gif
Is it possible to upgrade the graphics card as well?
written by John, September 17, 2008
Hi, I have a 24 inch iMac with the Radeon 2600 HD and was wondering is it possible to upgrade the graphics card as well to the 8800?
CEO/Lead Instructor
written by Dee, September 18, 2008
Great instructions, I have a (white Imac) 24" Intel core2 CPU T7400 @2.16Ghz and was wondering if these instruction would also apply? I just want to do the hard drive upgrade to a terabyte drive since I allready have 4 Gb of ram and Is it still SATA or just ATA hard drive? your feedback would be much appreciated.

Thank you in advance.

Dee Clay
Upgrading iMac white
written by Danny, September 18, 2008
I believe a very good guide to upgrade the hard drive in previous generation iMac white was written by John Wood - it's not quite the same upgrade as with iMac aluminum, nevertheless not so hard DIY smilies/smiley.gif

iMac white also uses a SATA drive (and you can see that from John's photo of inside his iMac white).

You might want to consider the following drives for your upgrade (the prices have significantly dropped on 1TB drives compared to the last year when this article was originally written!):

Western Digital Caviar 500GB hard drive (SATA, 16 MB cache) - $84 on 18-Sep-2008

Segate Barracuda 1TB, 32 MB, 7200 RPM - $139 on 18-Sep-2008

Good luck upgrading!


PS: Please let us know on how successful was your iMac white upgrade to 1 TB hard drive!
Can the CPU be upgraded in iMac aluminum?
written by Danny, September 18, 2008
Unfortunately I believe it is not feasible to upgrade the CPU in iMac 2007 models above 2.8 Ghz - Apple's 2007 product line. The reason might not be in the actual upgrade (replacing the chip) but in the fact that Apple motherboard (BIOS issue) might not recognize the newer CPUs (for example 3.06 Ghz) in iMac 2007 models.

The only way to test this is through a trial and error - I don't have the time or motivation to do it at this time, perhaps some of the readers will try if newer 3.06 Ghz CPUs will work in iMac 2007 - please let us know?

On the other hand I believe iMac 2008 models will most likely have no trouble upgrading the CPU to 3.06 Ghz (subject to socket verification inside the iMac!) - as Apple uses the same motherboards for the entire product line (and there is a 3.06 Ghz product in 2008 line up).

written by Mike, September 19, 2008
I am hoping you can help me. I am very comfortable building PCs. (2) days after the iMac warranty was up on my sons mid 2007 20" iMac the PSU went out. I ordered a new one. However I see no easy way or online instructions on how to replace this PSU and hope you can help. My son loves his mac and I am thinking of getting one but this is the 3rd mac product we have bought that has failed one way or other shortly after warranty period. In any case this imac is beautiful and I hope to help me son. I look forwad to your response. Thanks Mike
written by Danny, September 19, 2008

You should be able to follow the above guide - steps 1-4 in order to get access to the iMac power supply. The power supply is of a modular type hence once you open up your iMac (and remove the display as in step 4), you should have access to the PSU - and you need to simply take out the old and plug in the new PSU module.

Follow the steps 10 and onwards to close your iMac.

Apple machines are usually quality build and very durable. PSU failure (especially if you've had several machines fail) might indicate a potential problem with the in house electricity installation, or simply a problem with the power stability on the part of the grid you are connected to.

I strongly recommend using an UPS battery backup as it protects your computer equipment from surges, brownouts and blackouts - my lesson was hard learned as I've lost some of my equipment several years ago due to a thunderstorm (lightning causes voltage surges - a severe surge fries your equipment without the proper protection).

Since that experience I'm always using an UPS with my system and I've never had a single PSU or power related failure on any of my equipment!

Investment into an UPS battery ranges from $80 - $140 and is well worth for the protection it provides for your $2000 iMac!!!

For iMac aluminum the minimum UPS size you would use would be APC Back-UPS 550VA, and for iMac and your accessories (e.g. AirPort, Time Capsule, external hard drive, etc), you would need to use a more serious unit APC Back-UPS 900 VA.

Good luck replacing the PSU in your iMac aluminum! Don't forget the UPS protection as well!

written by Harold, September 19, 2008
Must the HD be formatted before installing. Or does the software also provide the disk utillities?

Formatting the hard drive
written by Danny, September 19, 2008

You do not need to format the hard drive prior to the upgrade as this step will be handled by OS X installation DVD.

Once you start the OS X installation you can choose the Disk Utility to custom partition and format the hard drive in any way you require.

You might want to check out this Apple web page on Leopard OS X installation.

1.5TB hard drive?
written by Toni, September 25, 2008
Can I replace my iMac 24" (late 2007) 320GB hard drive with Seagate Barracuda 1.5TB (ST31500341AS)?


Yes you can upgrade your iMac to 1.5 TB hard disk now!
written by Danny, September 25, 2008
Hi Tony!

Thank you for your question! As the hard drive capacities keep increasing, so do upgrade options for iMac!

It is my understanding that Seagate Barracuda 1.5TB was just announced - the product is to be available in couple of weeks. Nevertheless, I have reviewed the hard drive specifications at Seagate's web site and we have some good news - yes, you can now upgrade your iMac to 1.5 TB hard drive.

Therefore installing the Seagate Barracuda 1.5TB (ST31500341AS) following the instructions at this page is going to make your iMac one mean 1.5TB machine!

Please let us know how it went!?

Good luck upgrading smilies/smiley.gif

Upgrading iMac graphics card (?)
written by Danny, September 25, 2008
One of the readers above asked if graphics card can be upgraded on iMacs - I suppose you could use the more advanced 8800GTS graphics card from iMac 2008 and plug it into iMac 2007 and hence the upgrade graphics in iMac 2007 - this is due to standardized MXM PCI Express connector.

I've came across this graphics card upgrade for iMac white (not documented so well, but take a note of the last few photos of getting the GPU in).

Glue, heck no...but double-sided tape works great!
written by Hans, September 27, 2008
First, more accolades for the instructions. Clear as can be.

I just installed a Western Digital 1 Tb Black drive, without a hitch, replacing the 320 Gb on my 20" iMac. I would even say there is a marked performance increase, especially noticeable when suspend a VMWare fusion session. Awesome! smilies/grin.gif

Anyway, I had some double sided scotch tape, and that worked great on the temp sensor. I just affixed a small piece on each "wing" of the mount. Sticks great!

I did this as well!
written by Piethein Strengholt, September 29, 2008
Thanks for this manual. I replaced my 320gb harddisk a couple of days ago. I was able to replace the disk without detaching the cables of the screen.
written by archie bunker, October 06, 2008
Thanks for your effort in providing this info Danny, I just unpacked my 24" 2.8 today. I can now look forward to ripping the beast part when I fall out of love with the 320 GB WD, seagate should have the 2TB out by then!
A lifesaver
written by The MonT-SteR, October 08, 2008

I bought an iMac used earlier this year, and took the liberty of not renewing the AppleCare -- I've used Macs for years now, and they're reliable, so I figured I'd spare the expense. Wouldn't ya know that my hard drive up and died within a few short weeks after the complimentary AppleCare ended? Grrr...

I was nervous about trying the repair myself, so I called the Apple store. "Sure," they said, "we'll fix it, but you have to buy Apple parts." Thanks, but no thanks -- my money doesn't grow on trees, fellas. Another local repair shop was just so rude to me on the phone that I wouldn't go within a mile of their store. So, this had to be a do-it-yourself project. Actually, I had a couple Mac nerds at work help me.

The process was a snap, thanks to your guide. The pictures are excellent references. We had the entire hard drive transplant operation done in about 45 min, and my iMac is happily humming along again. And so am I. smilies/smiley.gif
Thanks so much for this Danny
written by Randy , October 08, 2008
Danny, how has it been so far with the Hitachi? How does it compare to the stock WD hard drive in terms of how quite it is? Any heat issues at all?
Hard drive ratings and comparison
written by Danny, October 09, 2008
Hi Randy!

Thank you for your question! I’ve had experience with various hard drives within the last year I’ve used in upgrading several iMac machines – my original Hitachi is working *really* great, it’s quiet, however runs a bit hot (up to 60C-140F – this is in the upper limit of manufacturer’s specification)... I’ve also had experience with (lower price range) WD Caviar 1 TB (16 MB cache) – this drive is louder than Hitachi and you can hear it working, runs relatively warm at about 55C-131F. Probably the best drive thus far I’ve had experience with in iMac machines is the (upper price range) WD Black 1 TB (32 MB cache, SATA 3.0) – it runs very quiet and also much cooler at about 45C-113F! WD Black was not available at the time of my original upgrade, however it’s probably one of the best 1 TB drive on the market today.

Please note that temperature of your hard drive also depends on your ambient temperature (it really makes a difference if your room temperature is around 20C-68F or on the other hand around 30C-86F) – therefore your actual temperature results will wary smilies/smiley.gif

In conclusion, my hard drive rating on this day [10-Oct-2008] goes as follows:

#1 - WD Black 1TB – quiet, runs cool, , 32mb cache, SATA 3.0, 5yr warranty
#2 - Hitachi Deskstar 1TB – quiet, runs warm, 32mb cache, SATA 3.0, 5 yr warranty
#3 - all others smilies/smiley.gif

Please let us know on your upgrade experience smilies/smiley.gif

Please update the instructions
written by Chris, October 16, 2008

Thanks a lot for this tutorial-I do have to say that I struggled a bit with the LCD removal on the 20" iMac. That is, until I read some comments that mentioned that I had to remove those screws on the side of the LCD. It wasn't mentioned in the instructions, so I wasn't sure, but after a struggle, I decided to try it, and lo and behold-the rest of the process went smoothly. I now have the WD Caviar 1 TB installed! I had hoped to use Carbon Copy Cloner to seamlessly copy my existing 320GB system disc on over, but it didn't seem to end up with a bootable drive. Luckily, I also have been using TimeMachine, and I am currently restoring from that!
All in all, not too hard a procedure-I had experience with iMacs in replacing the PSU and midplane assembly multiple times on a 17" G5 iMac, and this was about the same level of difficulty, ie, not too bad at all


written by Randy Walker, October 16, 2008
Thanks so much for the info on the WD Black Caviar drive; I went ahead and bought it the same day you responded smilies/smiley.gif

I was able to swap in the new drive in about a half hour thanks to your perfect step-by-step instructions! (thank you). Unfortunately, my Caviar drive runs no where near as cool as yours. As I'm typing this, I'm showing temps of 135F with an ambient temp of 81F. The room that I am in is showing 74F on the thermostat. The thing that is making me concerned is that I'm not even doing anything on the mac except responding to you, yet its still in the 130F range!!?? The mac has plenty of ventilation all the way around including the vents underneath.

What do you think? Should I take the drive back for a new one before I load it up with data? I'm sure it will fail rather quickly running at these temps, especially considering the max operating temp is 140F (according to the tech sheet).

Thanks in advance for any advice!!

written by Doug, October 16, 2008
I just upgraded my 24" iMac to the 1.5TB Seagate mentioned above.

No more space worries. smilies/cheesy.gif

Just take your time and be careful.

I noticed that the frame screws were of several different lengths. So that I didn't mix up where they belonged, I took a 8.5 x 11 sheet of paper and as I removed them from the frame I taped each one in the proper location on the paper with scotch tape. That way when I went to put them back I knew I was installing them in the correct location.

Thanks for the great article!
Reply to Randy
written by Danny, October 17, 2008
Hi Randy,

Good to hear you've managed to upgrade your iMac internal hard drive smilies/smiley.gif))

Your drive does run a bit hot, however as you say still within manufacturers specs (up to 140F, 60C). I would try to load the drive (e.g. start copying gigs of stuff back and forth) and see if it goes over 140F. In case it does, please contact WD support (online chat, email or phone), inquire on the issue, and try replacing the drive (perhaps the issue in your case is with the particular batch of those drives).

I believe that any drive operating within manufacturer's specs will not fail at least within its warranty period - and that being 5 years for our drives hopefully means we'll get at least that much life out of them (afterward we'll need replacing our Macs anyhow). I would be concerned if the drive exceeds the operating temperature (you need to do some testing on this) -- in that case you need to look into replacing it.

Finally, all of my data is backed up on an external drive (I use 1 TB WD My Book Studio with firewire 800) through Time Machine - I would *highly* recommend having an external backup drive regardless of the type of drive you are installing internally as having data copied in two places is the only guarantee of possible data recovery in case of drive failure!

Please let us know how it went(?)

could you
written by Steven, October 17, 2008
Danny this guide is absolutely brilliant, i have yet to upgrade my aluminium 20" imac, the guide you linked to about replacing the graphics card wasn't exactly clear, but i hope to read it a couple of more times to better understand it, and again thank you for being so daring to do this on your own. Thanks!! smilies/grin.gif
Cooling down the hard drive
written by Danny, October 18, 2008
In order to cool down the hard drive, you can use a really cool software utility called smcFanControl - use the utility to manually increase the minimum speed of the fan cooling the HDD (the utility also allows you to do the same for CPU and Optical Drive fan).

Standard system setting for HDD fan is 1100 RPMs - if you use the utility to increase this to 1800 RPMs (or even higher), the HDD temperature (as in my case) has dropped for about 9F (5C). You need to experiment a bit - increase the fan speed to various levels and measure how much your HDD temperature has dropped (you also need to allow the system at least 5-10 minutes to adjust to the new airflow - affecting the temperature reading). When you are happy with the effect (HDD temperature drop) leave the settings at that RPM level.

Another utility worth mentioning is iStatPro - a system monitoring tool you can use to view your HDD, OD, CPU temperatures (as well as other useful readings such as CPU utilization, memory utilization, network throughput, disk usage, average system load, battery capacity of your wireless mouse, etc.)

Great stuff !
written by Mathias, October 22, 2008
Thanks to your guide i was able to repair the Superrive who was stucked with a CD label inside !
You could just mention that there is 4 connectors under the screen, and that colors have to match (pink/gray and blue/gray)
Thanks Big time.
written by dorame, October 24, 2008
My machine is a year and one month old and was out of warranty when my 500GB HD went bad, Apple quoted me $350 to install a new 500GB HD and $450 for a Terra bite HD. Thanks to your guide I was done in 45 minutes. , lowes had a small TORX driver and bits for $6.00, I used a Pump Toilet Plunger, Don't fear It was NEW. The big precaution I took was to cover the screen when removing the screws. Comp USA had the seagate 1TB drive for $129.00. I had access to another computer and was able to reference the photo's, that helped also.
power connectors?
written by Samuel, October 30, 2008
First off, thanks for the great guide! Like many others my hard drive failed about a month after my warranty was up.

My only question is about what I can only assume are power connectors to the monitor. Mathias wrote about these but mine aren't color coded...well, the ones coming from the monitor are but not those in the computer.

I got my iMac like the day they came out(sept 07 i think), if that helps
Upgrade my BIOS revision
written by Jay Brice, November 04, 2008

I have a 3rd Generation 17" iMac 1.9ghz, and want to upgrade my memory to 2.5gb. Before i do this i was told i need to upgrade the BIOS revision. Please could you tell me how i would go about doing this?

Many thanks
faster superdrive
written by Lenry, November 15, 2008
It is possible to replace the superdrive with one that will write faster than 2x?
Lifting the glass with some tape adhesive
written by alex, November 25, 2008
I lifted the glass by putting 2 adhesive tapes in the upper corner. I used the stuff to seal packets, but simple tesa might be fine.

Overall great thanks for this article, it took me less than 30 minutes, the most difficult thing was to re-insert the display power adaptor...

great info!
written by Danimal, November 28, 2008
Thanks a lot for this guide!! I used it to install a 1 TB HD and a Ram in my new imac before ever even turning it on!! Great stuff! smilies/grin.gif
written by eugenetech, December 03, 2008
Thanks a lot I have to do this tomorrow. This is grad for the beginner tech in mac computers
Other iMac Mod's?
written by MacD, December 05, 2008
A couple of questions off the HD replacement issue, but obviously this process of opening the iMac would be the same for accessing other "replaceable" items inside an iMac.


Is the graphics card replaceable in the newer aluminum iMac's? I know the older (white) iMac's had the
graphics cards soldered to the logic board ... but I thought I read somewhere that the new iMacs (aluminum) have the graphics cards attached with plug-in connectors. That way Apple can simply fix a bad graphics card with out having to replace the entire logic board, as in the white iMac's. Considering the fact that the logic board replacements are costing around $800 - 900.00 (in the older white iMac's), this makes good sense to have redesigned the logic boards to accept "plug-in" replacements.

Has anyone replaced their graphics cards in the newer aluminum iMac's yet?
written by Dave Brown, December 07, 2008
this is invaluable. i will use this tutorial when i do my upgrade. thanks!
Also graphics card.
written by Andy, December 07, 2008
I have the 2008 20"aluminum imac 2.66mhz 2gb ram model.
And I was wondering also if the graphics cards would be the same size if I decided to upgrade.
Is their a difference between the layout, piping connections between the 20" and thye 24" models?
I wonder if anyone has tried this yet.
Thanks and GREAT guide.
NEW Tutorials on the way - CPU and GPU upgrade!
written by Danny, December 11, 2008
I would like to thank all the readers for their continuous support throughout the last year smilies/smiley.gif

Exactly a year later since my original hard drive upgrade on iMac 2007, I have upgraded my new iMac 2008 with 1.5 TB hard drive, and I've swapped the CPU and GPU (graphics card) in my old iMac 2007 as well -- expanding yet new frontiers on iMac mods -- finally we have the answer - yes, it is possible to upgrade CPU and GPU in your iMacs! it is also possible to replace the superdrive smilies/smiley.gif I've taken lots of photos, the tutorials are on the way, I just need to find some time during the holidays to write it up, hopefully before this year runs out smilies/smiley.gif

Merry Christmas to everyone!
Worked like a charm. Didn't disconnect the display
written by Terral, December 11, 2008
We have the 24" model and only disconnected the cable with two tiny screws on the bottom of the panel. I had my son hold the LCD as we tipped it up from the right side. I could then replace the drive while he held it. It was easier than I thought. A new HD in our laptop was much harder. The only thing to really watch for is dust. It was coming from everywhere. I tried not to breathe but it took about 20-30 minutes to do the whole thing.

Also, the backside of the glass had a film that really showed up when we tried to clean it. Lint-free wipes with lens cleaning solution did the trick. I was wishing for canned air.

One last thing. We couldn't find any suction cups anywhere in the house and used an apple peeler that sucks down to the counter. It even acted like a handle. Now we just need a bigger external drive to back up to.
Good Stuff - CPU & GPU Tutorial
written by SAS, December 14, 2008
I can't wait to see your write-up on the CPU and GPU upgrades. Thanks in advance. Would you please include information on where you found the parts?

Merry Christmas
written by Edilberto, December 19, 2008
All I have to say is nothing but the thanks to the great work that you did for us Thanks again and keep up no the good beacsuse it wasn't just good it was fantastic!!!!!! You are the Man!!!!
Awesome guide
written by Peter, December 21, 2008
I have used your guide this weekend after a hardidsk failure and i managed to do it without any problem this is really great!!!
My Imac was 1 month over warranty and they charged me euro 300 for a replacement of the 320gb standard hdd.
I didn't agree and asked to send it back unrepaired.
I bought the WD 1TB caviar for euro 90 and replaced myself using this guide!

Peter, NL

Great Read!
written by Dallas Miller, December 24, 2008
I was really not wanting to get into the system and poke around unknowingly and decided to look into how difficult it would be to replace the drive. This helped me so well tat I was able to replace the whole thing in less that 30 minutes. Great find here!
Easy as Pie!!
written by 15yr PC Guy, December 27, 2008
Thank you for the great read and the awesome description for the drive replacement. I am a 15 year PC person who recently converted to MAC and this was as easy if not easier than a PC hard drive update. The only downside was all the removing of Torx screws. Other than that, following the tutorial, this upgrade can easily be accomplished by an amature.

The hard part is waiting for Time Machine to restore my HDD smilies/angry.gif
written by rick, December 30, 2008
Great article and is there something going on here with the apple hard drives failing immediately after warranty? Mine failed 1 month and 10 days after expiration and I notice several other cases of that above....
written by Robert Guezen, January 04, 2009
Thanks. Great guide.

My iMac 24" is currently re-installing from a TimeMachine backup onto the newly fitted 1.5TB Seagate Barracuda.

Only hickup, there is PCB board on the spot where the temperature sensor was. So I had to move it a little bit. Hope this doesn't affect sensor accuracy to much?

Looks like I just had myself a new iMac 24"2.8GHz with 1.5TB & 4GB. Looking forward to performance gain from the faster harddrive.

Thanks again.
written by Robert Guezen, January 04, 2009
Up & Running. smilies/grin.gif

-1.16 TB free after system restore.

-110 MB/s HD performance. (old HD did 52 MB/s)


Thanks again.
How do you clone you old hard to the new upgrade
written by Bruce, January 05, 2009
This all sounds good, but please someone talk about how to clone you new disk once with all your programs from the old drive. Also is there any way to get an external SATA connection for IMAC 24.
Cloning disk = SuperDuper
written by Ron C., January 06, 2009
Copying the data is pretty easy, but take it slowly. These directions are largely product-type independent, but I'll try to drop some hints appropriate for an Intel Aluminum iMac. The description of most of the steps are shortened; I'm expecting a certain amount of intelligence and capability. If it seems like you don't know what a step means, then it might mean the entire process is over your head. I'm not intending that to be snide, just a warning that this is not an easy updgrade...

0) Purchase a new hard drive (SATA) and an enclosure (FireWire or USB2) of an appropriate size (both the new drive and the old drive are 5.25"). Install the new drive in the enclosure.

1) Format the new disk with the appropriate format (using Disk Utility, since you're doing an Intel Mac it needs to be GUID Extended, Mac OS Extended (Journaled), but double check - whatever it is, it should be the same as the current drive).

Your new drive is now useful, but quite empty. Let's get something onto it.

2) Download SuperDuper (http://www.shirt-pocket.com/Su...ption.html). You don't need to purchase it, but if it's helpful you might want to remember that...

3) Using SuperDuper, copy the old disk to the new disk.

At this point, you have cloned your disk onto the new drive.

4) Remove the new disk from the enclosure.

5) Install the new disk in the computer, using the above directions.

6) Take that old disk and install it into the enclosure. Voila, instant bonus storage.

CPU/GPU Upgrade Guide
written by Dominic Rivera, January 07, 2009
Looking forward to reading the GPU/CPU Upgrade guide. I've got a 2.0Ghz 2007 iMac that I'd like to upgrade, but I only want to dig around inside there once so I'd love to see how to upgrade the CPU/GPU and then do a massive warranty-voiding upgrade all at once.
Be careful with the screen cables
written by jean, January 11, 2009
After doing the hard drive change, my screen wasn't working as I've had difficulty with the third screen connector, so I checked there and I didn't push back correctly this connector (this connector is hard to reconnect correctly).

To help you, I suggest to remove 4 screws holding the power supply board (the board where you connect this hard-to-push-back-connector). With this board removed do not unplug any wires -- it's not necessary to lift up the board -- it will be really easy to remove and put back.

I put everything back and now it's working!!

My new Samsung spinpoint 1TB is working great! (it does not make more noise than my old 320GB, and the temp is about the same - 45 to 47 C).

Now, where I can find these non-glossy screen protectors !?? :-)

I copy the old drive to the new one (I put it in a USB enclosure) with Super Duper, and everything works like before, except my bootcamp partition -- I'll reinstall it, I only have Crysis on it....
iMac HD Replacement
written by Ajward, January 12, 2009
Excellent presentation!! I just bought a 20 inch, 2.4GHz and was wondering how difficult it might to swap the drives. Not a priority at the moment since I have about 800GB on external drives.
Nice to know the information is out there though.
24" iMac w/ 1.5TB HDD!
written by Brutus, January 13, 2009
Thank you so much for your detailed step-by-step guide. I wouldn't have had the confindence to upgrade the hard drive without your guide.

I successfully upgraded a refurbished 24" Aluminum iMac 2.8GHz (April 2008 model) to have 1.5TB HD & 4GB RAM! By buying refurbished, and doing the HD & RAM upgrades myself, I saved myself over $450 and have more storage capacity than is available through Apple!

Again, Thanks so much!
3.06 Intel core 2 duo
written by Mike, January 13, 2009
Can upgrade be done with this?

3.06GHz Intel Core 2 Duo
2GB 800MHz DDR2 SDRAM - 2x1GB
500GB Serial ATA Drive
NVIDIA GeForce 8800 GS w/512MB GDDR3

I just bought it and haven't taken it out of the box yet.
I also found a certified mac tech who said he will install it and not void the warranty. I hope he's not BSn me because I bought the apple care plan.
Yes, you can upgrade hard drive in - 3.06 Intel core 2 duo
written by Danny, January 13, 2009
Hi there,

Yes, you can upgrade the hard drive in 3.06 Intel core 2 duo, the instructions are 100% the same. Actually, I've upgraded one of those just the last month to 1.5 TB Seagate, works very well.

Volunteers bloggers needed
written by Danny, January 13, 2009
Hi everyone,

I haven't got the time to post the upgrade of CPU and GPU as of yet, sorry folks, hopefully it will be coming online soon. I was also planning to post some of the other (cool) things I've done - like upgrade Apple TV with 500 SATA drive (that normally can't go in there) and there are also other ideas in the pipeline... The only restraint I have is lack of time (I have a busy life too smilies/smiley.gif), I was wondering if there are people out there willing to help out and perhaps launch a dedicated web site that would be dealing with all these cool mods... Just sounding the idea, if some of you are interested in helping out, please drop me a note at danimir at gmail dot com

Thank you everyone!

installing OSX to new HD
written by Mike, January 14, 2009
Thanks for your quick reply to my previous question. I will be buying the WD Caviar black 1 TB and the Kingston 4gb 800 MZH memory. I've heard about some problems with the Seagate 1.5 TB so I'll pass on that one.

Anyhow, I'm new to mac so I don't really understand the OS yet. As I said earlier I haven't even taken it out of the box yet and don't plan to until I have the new HD and memory ready to install.The OS reinstallation part of it is what scares me the most.

Since my Imac is new I would assume the latest version of OS X would be on the install disc. So would the following apply?

On the other hand, if you have the full version of Leopard OS X, just go ahead and pop in the DVD, turn on your iMac and it will boot from the DVD - just follow the instructions on the screen to install the operating system.

Please note that once you are booted to OS X Leopard installation you will need to start the Disk Utility in order to partition and format your new 1TB hard drive.

Is there a default setting during the install that creates partitions the way it came from apple?
Any replies welcome.
osX install
written by thinkdunson, January 15, 2009
first of all, relax. there is absolutely nothing to be afraid of. it's all extremely easy.

the install disk is also a boot disk. it was the latest version of osX when they packed it to ship, but there could have been an update since then.

the way it came from apple is with only one partition. so all you need to do is
open disk utility from the menu bar,
select your disk from the list on the left,
name it,
select HFS extended and journaled,
then just click the "erase disk..." button and confirm.
(i'm on a pc at work right now, so don't freak if the names of things i just mentioned aren't exact.)
then install osX.
the installation is also extremely easy. just do the default or easy install.

when you see it, you'll see how simple it is. apple did all the worrying for you, before hand.
One little screw lost.... take care
written by Josh, January 16, 2009
Just upgraded my 20" iMac (Late 2007) with a Samsung Spinpoint 1TB. Works great.

One warning to everyone: The two teeny screws holding that display connector are very tricky. I lost one in the guts of the machine when removing it! Now there's only one screw holding that connector in. I don't think (at least I hope) that this should be a big deal. Can a microscopic little screws just sitting somewhere in there cause any electrical shorts or anything like that? Do any more savvy users know?
Strange sound Hitachi 1TB?
written by Rick, January 17, 2009
Hi all,

I followed this great guide to install a Hitachi 1TB in my late 2007 iMac 2GHz. Everything seems to work fine, but I keep hearing this strange sound. It's a constant 'tick tack' sound coming from the harddrive every second. Like it's being accessed, even when I'm not using the computer. The drive has been in my G5 and I didn't notice the sound then.

It even happens when I just boot up the machine so I don't think it has something to do with heath.

Any ideas on this? Is there a diagnostic softwaretool I can use to check if the disk is still ok?

Thanks in advance and thanks again from this great guide!
Hard drive clicking
written by Danny, January 17, 2009
Usually when drives start making loud clicking sounds it is time to backup your data and look into replacing the drive as soon as possible. Not sure on the type of the clicking sound you have and how old is your drive (you say it has been used in your earlier G5) - in any case, you might want to consider backing up your data (if you don't have your time machine backup that is) and use some of the Mac diagnostic tools described in this article:


Hard drive clicking
written by Rick, January 17, 2009
Thanks for your reply Danny!

I just bought two of those drives 3 months ago. They were brand new. Unfortunately no warranty because they are HP spare parts and are normally not sold without a machine.

Could the problem be caused by installing the drive on its side? When I had it in my G5 it was lying flat.

Something else: the disk is not slowing down my machine, that's also strange. And I also noticed that the ticking is less loud and less often in Windows XP (I have a 900GB partition for OS X and 100GB for XP).

Going to check the site you suggested right now! If the problem cannot be solved I might install my other 1TB that's still in my G5. Maybe this will solve the problem.

Thanks again!
Noisy HDD
written by Danny, January 17, 2009
Hi Rick,

It also could just be that the drive you are using is simply loud - if using one of the utilities I've told you about earlier shows that everything is OK with your drive. Again, I cannot distinguish the type of clicking you have - usually *very loud* clicking and grinding means the drive is about to go bad, on the other hand a quieter clicking and moving is attributed to a normal operation of the drive - whereas the sound levels depend on the drive quality and type used (please have a look at the recommended drives at the top of this page and user feedback in the comment section).

It shouldn't matter if the drive is installed on the side. However, if you noticed it while installing the drive, the pins on the drive's side go into a round shaped rubber holders that are in fact providing shock absorbing (hence reducing the noise). Perhaps something didn't go right during the upgrade and pins are in direct contact with the chassis transferring the vibrations - again just a hypothesis.

If the problem persists, and if everything is OK with your drive once checked with the disk utility tools, you might revise the installation steps and perhaps consider installing another (quieter) drive.

Good luck,

written by AJ, January 18, 2009
Has anyone considered the Western Digital Green for the iMac?

reportedly runs cool, quiet an low power consumption. Sounds good for this application. Performance is less but approaches the Western Digital Black.
CPU VS Bus speed
written by Donald McHose, January 18, 2009
Looking at the offering for a CPU upgrade in the future it looks like that anything over 2.8 MHz ( what I have ) is for a 1333 bus since our macs run on a 800 bus would this be an issue or is it just CPU bus speed by what ever the cpu is clocked at ? I have read were the E8600 was clocked at 3.8 with no issues ;-) WoW!
Works like charm!
written by Gsa700, January 19, 2009
I just upgrades my 2.4 C2D to 4 GB and 1 TB HDD!

I used kingston hyper-X 800 mhz and WD Black 32 MB 1 TB drive.

I am restoring from TIme Capsule as I write this.

Replacing Optical Drive
written by Moshe Braun, January 19, 2009
I purchased the 20 inch imac Aluminium 14 months ago. Last week my optical drive went crazy and is onow out of commission. I bought a replacement (Matsia UJ 875). Is it terribly dificult to replace this part. Also, I noticed there was some silver tape attached to the drive. Is this of any significance?
written by David, January 20, 2009
After reading your article I decided to take the challenge and build the ultimate iMac on a budget. Today my refurbed iMac 3.06 24", 500gig HD, 2gig RAM. arrived $1,900, along with a Seagate 1.5TB drive from Amazon $140, and 4 gigs of RAM from Crucial about $50. Right out of the box I upgraded the drive and the memory with no real problems. I am now installing the operating system.

1. The glass was easy to pop out with only two large bathroom hook suction cups.

2. It was easy to disconnect the camera wire.

3. It took me awhile to locate the two lower display connectors.

4. I never could disconnect the display power connector, so I just rotated and laid the display carefully to one side. I then exchanged the drive.

5. It took me awhile to figure out how to format the drive (being new to Mac) and install the OS.

Just take it slow and read all the notes several times before you go for it. I could never have done this without this website. Thanks so much.

......and now what can I do with this souped up machine?????

Reply to questions
written by Danny, January 20, 2009
Hi everyone!

Thank you for your awesome interest in this page! Here are my answers to couple of your questions above:

- Can you use WD green 1TB hard drive? Yes, by all means, it runs cooler than all other drives and uses the least power -- however you trade in the performance as this drive will perform slower than all other recommended at the top of this page. If you are the type of user that does not require peek performance from your machine, you might consider having this drive. In terms of noise, I don't think other drives (WD Black, Hitachi, Seagate) are all that noisy in iMacs (also a matter of individual perception), so you might not have a lot of gain there.

- In terms of CPU upgrade - higher CPU bus speeds are backward compatible, so if you use a CPU with high freq. bus on a lower bus motherboard, it will work, however you won't be getting the performance gain. Actually the bus and CPU frequency is automatically being determined by iMac boot loader (we'd call this BIOS in PCs). iMac hardware is the same as used in laptops - hence you'd find Mobile CPU socket in there, an optical drive used in laptops, a MXM graphics card used in laptops - it seems Apple uses the same components in all of its product lines (they are all mobile platforms) - it sure saves the manufacturing cost. Having said that, iMac uses "M" (mobile) socket for its Intel CPUs, hence if the CPU you are putting in fits the socket (being M socket), it is most likely it will work and be automatically recognized by the boot loader. I've actually experimented with several CPUs back and forth between iMac 2007 and 2008 (the difference being 800 Mhz and 1333 Mhz bus speed), and they worked well back and forth. The only thing that didn't show up properly was the CPU type in "About this Mac" if you use other Intel Mobile CPUs than the ones used by Apple -- you do get the performance of the CPU though, its just not being recognized properly in About this Mac - but I suppose most of us can live with that for the additional performance gain. I didn't have the time as of yet to write a page on my CPU upgrade experience in iMac -- thanks everyone on the patience though smilies/smiley.gif

- Upgrading the Optical drive - it requires you to take the right hand side speaker out and to unplug quite a few connectors from the motherboard in order to reach the optical drive. I've actually replaced an optical drive for a friend of mine, it was a bit more complex than upgrading the hard drive, but not too much. Please take a note of all connectors you are pulling out, they must go back where you pulled them from. Luckily they're all different sizes, so you won't be able to mix them up, they're even color coded. The silver part is just a shielding (connected to the ground), and at the end of the day you can live without it. What's important is that drive is connected to its connector at the back giving it power as well as communication with the motherboard - and putting it all back nicely so it fits. Don't forget to plug back all the connectors too! Once I've forgot to plug in a connector, and when I've powered up the machine, the cooling fan was spinning at its max! Had to open the machine again and locate the connector that wasn't plugged in. I took some photos of my optical drive upgrade, hopefully I'll have some time to make a page on this upgrade too.

Thank you everyone for posting your upgrade experiences and issues at this page!

optical drive
written by OddyOh, January 20, 2009
I've got a 20" Aluminum iMac, and there's a DVD stuck in the optical drive. I'll try opening up the iMac tomorrow, thanks to this great tutorial! I don't even care if I can't get it out, I just want to disconnect the power to the drive so it'll stop spinning everytime I open an app. I've got a faster external drive anyway.
Optical drive - stuck DVD disc
written by Danny, January 21, 2009
If you have the patience you might be successful extracting the stuck DVD disc with a pair of tweezers...

Ultimately you can take the drive apart (you will need precision screwdrivers) and extract the stuck disc that way. The extent of damage will determine if the optical drive is reusable (e.g. if the laser head or some of the moving mechanisms got damaged).

If your optical drive is beyond the repair, you can look for a replacement optical drive online - 8X DVD-RW drives that would go in there are UJ-875, UJ-857 or UJ-85.

You can actually fit any laptop-style slot loading parallel connection (ATA) optical drive in there, even older models UJ-825, UJ-846 and others (these drives are less capable, slower or no DVD recording, you need to check the specs).

Seagate 1.5 TB drive in iMac 2007, 2008 (hard drive firmware update)
written by Danny, January 24, 2009
The gear I use daily is iMac 2008 with Seagate 1.5 TB hard dive - I didn't have any problems at all with it, however in some *very rare* cases (and with the very first models) manufacturer notes that these drives might experience data inaccessibility problems -- Seagate is also claiming this can be easily fixed with a firmware update. Here is a great article on the subject:


Although everything was great with my Seagate 1.5 TB, I've went and ran the hard drive firmware update - in my case I've went from version SD17 to SD1B. You need to locate your HDD model - click on the Apple logo, then About This Mac, then More Info, and finally on Serial-ATA tab - there you will see hard drive model and revision - which is the firmware version. Look for the model number and match it at Seagate's web site and download the ISO file, burn onto a CD and boot from it, follow the instructions and the firmware in your iMac's with 1.5 TB will be updated, reboot and you are all set.


PS: you are doing this at your own risk, make sure you have all of your important data backed up!!! smilies/smiley.gif
Samsung hard drive?
written by muk546, January 29, 2009
hey very nice guide i just have a question do you think this hard drive will work


Seems like its too cheap anyway could someone tell me if this drive is a good one its from Samsung
Another upgraded 24" IMAC to 1TB HDD & 4GB SDRAM done by a rookie
written by Mike, February 01, 2009

I had no experience working on computers before this. I bought a WD Caviar 1TB HDD and the Kingston 4GB Apple upgrade kit.

I had my wife help me (extra hands) and together we upgraded our new IMAC in about 45 minutes. It was very nerve racking opening up a brand new (refurbished) IMAC, but taking our time and referring to the illustrations gave us the confidence to do this upgrade.

After pulling the plastic screen with 2 suction cups on each corner, unscrewing the bezel and flipping it over leaving the camera connector alone (it came unconnected by itself after flipping the bezel over), unscrewing the 8 screws that hold the LCD, removing the 2 screws on the LCD connector on the right bottom of LCD (be extra careful not to drop those tiny screws) I did not disconnect anything else (wire on the left side or the connector under the LCD) to access the HD. I had my wife hold the right side of the LCD up and I was able to reach in and remove and install the new HD.

Reapplying the temp sensor was a little tricky trying to locate it in what you think is the right spot. We put it exactly where it was on the old HD. Just off the center right next to but not on the aluminum circle. I was lucky enough to still have enough adhesive on the sensor holder and foam to stick it back on the new HD.

Putting everything back was easy except for getting the suction cups to release from the screen cover. It took about 10 minutes to gently get them off with the only casualty being one of the guide pins (alignment post) breaking off.

Thank you for for these easy to use instructions for this huge upgrade!

home user
written by brian, February 03, 2009
thanks for the great directions. I changed my 20" aluminum mac hard drive in about 15 minutes. I didn't disconnect the lcd cables either. It lifted up with enough room to get the drive out.

Unfortunately, something is misaligned with the optical drive. I had a disc in there which wouldn't eject after reassembly. I had to take the aluminum bezel off to get the disc out.

any tips on proper alignment of the optical drive before I put the bezel back on?

Socket for CPU
written by Vincent, February 05, 2009
Hi Danny,

First of all, thanks a lot for this guide - I've been wanting to upgrade my 320GB drive in my 2.4Ghz 24" imac for a long time now, but never dared to take the plunge. Now however, I feel confident, and am going to upgrade asap.

I do have a question concerning the CPU-upgrade however. In you post of januari 20, you state that the socket used is socket M. However, when I look at CPU's online, I can only find socket P CPU's. Are the socket M CPU's even for sale anywhere? Also, Wikipedia states that the socket M is obsolete and was replaced by socket P.

Thanks again, I eagerly await your CPU upgrade guide!

Success! Thanks for saving me lots of money!
written by Brian Talbot, February 06, 2009
I just successfully replaced my 500GB Hard Drive in my 24" iMac 2.8GHz Core 2 Extreme (which failed after 13 months... figures), with a 1.5 tb Seagate. It was simple with these clear and useful directions and it only took me 20 min. When I booted it up for the first time it wouldn't load the CD, so I started it in Target Drive mode by holding "T" as it started, then used my macbook connected with firewire to reformat and install the Mac OS Disk Drivers. Then I booted it up with the leopard disk and restored my system from time machine. Such a relief, after a week of hassle trying to figure out what went wrong, to see my computer restored.

I read up on the Seagate 1.5TB Firmware issue, and if you go to Seagate's website, you can enter your model and serial number and it will tell you if your drive is affected, and needs a firmware update. The steps to find out if your dirve needs a firmware update are located here:


My drive was not affected by the firmware issues.

Thanks for the great tutorial!
Worked! Thanks!
written by Brian Juskiewicz, February 07, 2009
I managed to do this switch without removing the power cable for the LCD screen. I just simply had a friend keep it vertical while I did the work on switching the hard drive. My hard drive catty was very hard to remove and took many times more force than I thought it would have. I would recommend unscrewing the handle if yours screen is off - it will make you less nervous. The only other thing with my change was that my glass had some kind of coating on it, and streaked when I placed it on bed. Took many many nervous cleaning of the inside of glass. I cannot stress enough how thin the glass is, and that it will actually bend if you are not careful. In the end, my 1TB WD hard drive works like a champ and I am happy I did it. Thanks for the guide!
May I use your iMac Alu tutorial translated in french on my site ?
written by MacBoostFR, February 08, 2009
Hello dear MacUser,

I have a french website (MacBoostFR) dealing with take-apart guides of Apple computers and peripherals.
I just put online a rare guide on taking apart the iMac G5 iSight 20" : my guide is detailed and richly illustrated, so that french and non french readers can easily understand the different steps.

Your english step-by-step tutorial is EXCELLENT ! I'd like to translate it into french, with your pictures (until I do mine, tutorial and images) so that the french community can share it.
Of course I'll mention copyright AMFITEATAR (or whatever u want : the name of the person who did it).

Let me know your opinion on my demand.

Looking forward to reading you soon and hoping you'll accept my project.
MacBoostFR (Guillaume)

Really easy, thks!!!
written by Patrice Juillard, February 09, 2009
Just did it after crash disk. Under the screen 4 small connectors. IMac bought in Switzerland perhaps different than yours. But with patience and calm (my 3 chidren at school) it was a pleasure to do this. Thanks very much.
written by Alex PR, February 09, 2009
Thanks a lot a upgrade my imac step by step
written by Mike , February 16, 2009
WOW!!! Thanks for posting this!!! My 24" Mac silver is better than ever. I had the stock WD 300 gig and it was full, the system had slowed down. I followed your walkthrough putting in a WD 1 TB drive, all went as you said, there were 8 side screws that had to be removed in order to lift up the screen, but other than that it was quick and easy. Thanks.
Some finer points of the hard drive installation
written by Vincent, March 03, 2009
I just upgraded to a 1.5Tb Seagate, and while I still remember them here are some issues I encountered.

I used suction cups from a car sun shield. I'd never used the cups as the sun visors hold the sun shield adequately anyway.

Don't tilt the glass too much, it can bend the locating pins. Try to lift it off evenly.

That little connector on the left with the four fine wires going to it is quite tricky to remove. Don't pull the wires or they will come out of the connector, and don't use pliers like I did because they can damage it also. If you can, I think the best thing to use is your fingernails each side of it.

I found it easier to lever off the connector with the two screws than to pull on the tab. It's quite tight.

There's a little piece of plastic with a hole in it, about 5mm x 15mm, directly in the centre at the bottom of the lcd screen. When I lifted the screen it got lifted off where it was mounted. Just be aware of that and don't lose it.

I disconnected the camera connection, but it would be easier not too. I didn't disconnect the main lcd cable, I just tilted it up to get access inside.

Take care removing the cables to the hard drive, the plastic connectors are very soft and seem to mark easily. I undid the screws but still levered the handle with one handle of a pair of pliers.

I put a piece of thin aluminium on the locating pegs of the hard drive and then gripped them with pliers to get the pegs out. I noticed they'd been loctited in, but didn't worry about putting loctite on when I installed them on the new HD. I can't really imagine them vibrating loose.

Replacing the temperature sensor is tricky as the drive was different and I couldn't get it on the exact same spot. Just took an educated guess on that one.

If the lcd doesn't sit evenly when you reinstal it check for wires, especially the camera one if you've disconnected it.

When installing the front cover, it pays to poke that silver conductive tape or whatever it is around the RAM slot in. If it's not tucked in it's hard to get the RAM back in properly.

I cleaned the glass and lcd screen with the cloth from my glasses case. There was a lot of screen removal and replacement as I kept spotting dust on the inside of the glass and on the screen, but I got it pretty good finally.

I only needed a T8 and a T6.

And now that it's all up and running I've just noticed on the underside of the Western Digital HD I removed there's a SMALL PIECE OF FOAM WITH THAT SILVER CONDUCTING STUFF AROUND IT, STICKING TO IT. I assume this gets the static electricity off the drive, so tomorrow I'm going to have to go through this exercise again and put it on the Seagate. Wish I'd known about that . . .

Delving into the iMac's innards was an intense experience. Only damage I did was to the lcd connector on the left, but it still seems to work fine. My advice is to be patient and not force anything. Good luck to you all.

written by Danny, March 03, 2009
Hi Vincent,

Thank you for describing your experience so vividly to us.

I would like to state for everyone here that all connectors are to be handled with your fingers (as shown in photos), there is absolutely no need to use pliers to remove any connector in iMac (and risk the damage).

In terms of the temp. sensor for the hard drive, if the drive is different, you can put the sensor anywhere it fits on the drive as this is an external temp. sensor whose readings are used to calculate the RPMs speed of the cooling fan (the temperature will also dissipate almost evenly through the drive's metal casing), so no worries as to where exactly you put it on the drive.

The foam with the conducting stuff around it, if we're thinking of the same thing, is the EM shielding, and your iMac will work just fine without it (the drive is already grounded when connected) - there is no need to go through the experience again just to put back in that little piece as you won't notice any significant gain or change in performance.

Thank you for that comment on tucking back the silver piece around the RAM slot in order to make the front panel go back easily - I remember I've experienced the same issue and I've updated the above instructions with this info! smilies/smiley.gif

iMac Problems
written by fatalfred, March 03, 2009
First of all, I would like to thank Danny for your awesome DIY!!! And all the others who have commented and shared their experiences. It was and still is a great read!
I am slowly building up the courage to do this soon, but waiting on your other tutorial concerning CPU and Graphics Card.
The reason for this is that I recently had some problems with my late 2007 iMac screen (irregular coloring from left to right, vertical lines etc...) After reading on online what causes it, or possible fixes, I seem to have corrected the vertical line by increasing the internal fans but not the irregular coloring....

Did you notice any of these problems with your model?
Will a Graphic card update solve the problem?
Any insights to this would be great.
Screen problems
written by Danny, March 03, 2009
Hi fatalfred,

Thank you for your post.

It is a well known fact that iMac 2007 LCD screens have discoloration problems (uneven colors, especially at the screen edges) - I've actually had the same discoloration issues with my iMac 2007. Since then I've replaced my computer with iMac 2008 and they have *much* better LCD screens, brighter, stronger colors, fewer discoloration problems.

The only thing you can really do is replace the LCD screen (the issue has nothing to do with the graphics card). If you still have the Apple warranty (or extended warranty), you might want to contact Apple for replacement. Other than that you're out of luck, or couple hundred bucks out of your pocket if you really want to pay for the new LCD screen replacement. It actually might not be that expensive if you purchase one directly from China (Shenzen) and replace it yourself (easy to do, just plug it in). However you'll need to research the Chinese suppliers on your own. Another solution (arguably economically more feasible) might be to sell your iMac 2007 on eBay and buy a new one.

The new iMacs 2009 are available as of today with 4GB RAM and 1TB hard drives built in (however still no 1.5 TB models).

written by Barry, March 04, 2009
Hi all,
This has been a fascinating read and I've been thinking about tackling it for a couple of weeks. Anyway, I've just done a "dress rehearsal" by taking of the front panel and was surprised at just how EASY it popped up. That excersise has given me the final confidence to give it a go - I'll go buy a Seagate 1.5T drive tomorrow.

Anyway, the exercise has also lead to a question/comment. You keep referring all the way thru to the "front glass panel". My iMac was bought in late (December) 2007 and I'm pretty certain the panel is plastic - or it definately feels that way. VERY light, VERY easy to remove and sounds like plastic if tapped - could this be right?

Anyway, let you know how I go after tomorrow.
Glass or plastic? (acrylic glass)
written by Danny, March 04, 2009
Hi Barry,

I believe the front panel is made of the actual glass and not "plastic" (acrylic glass or plexiglas) as I don't believe plexiglas could be that much reflective (glossy) - on the other hand I might be wrong. What's your opinion?

written by Barry, March 04, 2009
Hi Danny,
It certainly doesn't "feel" like glass in the classic sense. It's very light and, as I mentioned, sounds more like plastic if you tap it. Anyway, for those interested, it comes out VERY easily. I was expecting to have to really pull at it and then have something heavy like a sheet of glass that big would be, but it wasn't. Now to take that next leap and go further smilies/smiley.gif
written by Salmacis, March 12, 2009
Thanks for the guide, helped a lot. I managed to upgrade a 2008 iMac to 1TB now. However, it went not as smoothly as it should - The LED Temp cable came in the way of a screw when assembling the whole thing again. Yes, the screw was a bit tighter than usual, but I didn't realize I was screwing in a wire actually! Well, after starting the Mac, all fans were at full speed, which was unusual. So disassembled again and saw that the tape around the four wires of LED temp was damaged. Now everything was clear... probably there was a short circuit there (caused by the Torx screw) and so the Mac believed the LED temperature to be at Maximum, that's why the fans rotated at full speed. Well I was fortunately lucky, the cable was not that damaged, so after taking care there was no screw in its way, the Mac started normally *Phew*.

Kind of unlucky here though, as the wire must have moved over the hole for the torx screw (actually, it was the second of the long 4 bottom screws seen from the left) while I put the frame back to its place... So maybe the guide should have that caveat... Apart from that, all went well, but 1 or 2 helping hands are a good advice (especially for the LCD connectors...)

written by Barry, March 13, 2009
Hi Danny,
I wrote a few days ago about whether it was a glass or plastic front. Now I've upgraded my HDD and am wondering whether there are different models for different countries as I've found some other differences which I'll outline. I live in Australia and my AL iMac was bought in December 2007.

First difference is, as I've stated, the "glass" panel definately feels like plastic - it is VERY light, sounds like plastic when you tap it and came out with no real effort at all.

Next, there are a different number of torx screws around the aluminium frame. There are 4 across the bottom and top and another 2 down each side. I read notes stating that they were all different sizes - I actually found that the 4 along the bottom were all the same size as each other and were longer than all the others which were also the same as each other - ie only 2 sizes total. (Hope that made sense)

Next, and this confused and stopped me in my tracks for some time - the 2 cables to the LCD are not the same as your photos. I eventually found one at the lower left of the board and only by blowing up your photo and noticing the "pull" tab on the other was I able to see something similar high up on the upper edge of the board approximately 8-10cm from the right. It's almost directly connected to the LCD panel.

Having got that out of the way, I lifted the LCD panel and found, instead of a single power cable to the left, there was 2 pairs of paired cables on the right. One pair at the top and one at the bottom. They had small connectors each to matching cables on the LCD so were easy to remove.

After that, everything else was as you've outlined. I've now got 1.5T of storage up and running beautifully - that tip about booting straight into the Leopard upgrade disc was great and certainly saved some time!

I downloaded and installed some temp monitoring software you suggested and the Seagate drive runs consistently at 49C.

So, it would be interesting to see if there are differences according to the country the unit is sold in. Great article though and for anyone contemplating, very easy - PROVIDED your comfortable with getting into the insides of a PC/MAC and you know how to take care and patience.

Be careful...
written by Salmacis, March 13, 2009
Hi Barry,

I can confirm that my 20" iMac also had only 2 torx sizes for the frame (not 3) and I also found the same cables as you connecting the LCD panel. I live in Austria (not Australia smilies/wink.gif

The lower one of the paired cables (LCD power) also made troubles after assembling. It somehow got in the way of the fan for the optical drive, which made a weird sound. So I had to open the Mac again (for the 3rd time now - getting an expert in the meantime smilies/wink.gif and move the cable a bit. Now everything is fine, but take care, there are a lot of pitfalls here (see also my previous comment here on the LCD temp cable).

Happy tweaking,
written by Daniel Reilly, March 15, 2009
No that was not the sound I heard when I pulled off the screen. smilies/wink.gif But the sound I made when I finished this project. It was really one of he easiest swaps I ever did. I only had to remove the video clip on the lower right and the little plug on the left. Then if you carefully pick up the screen you can slide it back and tilt it u to remove the HD. I was by myself so I used my trusty OSX DVD box to hold up the screen. The hardest part was trying to get that damn clip the holds the HD in. I finally unscrewed it and pulled it out. I put in a brand new Seagate Barracuda 1TB that was manufactured on 2/17/2009. I'll still check to see if it needs a firmware update by I don't think so/.

Thanks for this grand guide.

Dan Reilly
An easier approach
written by DOBM, March 15, 2009
Many thanks for your guide and photographs. I don't think I would have attempted the hard disc upgrade without it. I did however find a few differences to the described for my 2008 iMac. There are Torx screws in the frame of the LCD which need removing once the from Bezel is removed. I didn't need to unplug the camera or the LCD connectors. I hinged up the top of the LCD with a can of compressed air, but anything would do, perhaps a couple of bits of wood would have been better. This gave ample room to remove the drive. I found a T9 screwdriver fitted every screw I needed to remove, even including the locating PINS on the original drive. I didn't want to risk the bathroom sucker approach and purchased a professional suction handle (which consists of two large suckers with air clamps attached to a handle). This cost just under 50 Euro but gives great piece of mind. The compressed air is also VERY worthwhile, in fact I managed to reassemble first time with no dust between the glass and the LCD.

So thanks again and well done!
thank you
written by Eric Peirce, March 15, 2009
just got done replacing the drive on my son's mid 2007 20" iMac. a few steps were different than your DIY but nothing too hard to figure out. there is actually four small connectors under the display rather than one bigger one. installed leopard now, everything smooth so far.
thank you again!
Open iMac Video
written by stereocilia, March 16, 2009
Here is a video of the same procedure described on this page
Thank You!
written by Chris, March 23, 2009
I was weary about tackling this project until I game across this awesome guide! The detailed photos and write up convinced me to give it a go. I picked up the tools necessary and had everything done in probably 45 minutes or so.

I got a little hung up on which cables were the LCD cables. I ended up unscrewing the LCD (8 screws - 4 on each side) and gently lifting it up and seeing which ones you were talking about. Like another commenter, I ended up just removing the bottom left and right connectors and letting the LCD rest on its side in a towel against the wall. The third "connector" seemed like there were 4 of them? A couple on the bottom and the top, but I didn't need to remove them.

Thanks again for the detailed writeup! I'm going to pass this guide along to some friends that also have iMacs. I'm restoring from Time Machine as we speak!! smilies/smiley.gif
It was the tape on the back of the LCD...
written by Salmacis, March 24, 2009
BTW, it was not the LCD power cable that made a strange sound. There is some tape on the back of the LCD around the DVI connector - this tape went off a bit during the procedure and touched the optical drive fan on its top! Put the tape back and now it's silent (Now I opened the iMac for the 5th time or so smilies/wink.gif So be careful...
written by Christian, March 24, 2009
Can you recommend the

Western Digital WD15EADS 1,5 TB (Caviar Green)

or is this one better? smilies/smiley.gif

Maxtor STM31000340AS
HDD choice
written by Danny, March 24, 2009
WD Caviar Green has slower data throughput (5400rpm), uses less power (hence less heat), and is very, very quiet, whereas with Maxtor you will have a better performance - faster data throughput (7200rpm), it will use more power (higher temperature dissipation) and won't be totally silent. Your choice is between performance in data transfer rates vs heat and noise.

Good luck!

Screen Fuzziness/ interference?
written by Migsy, March 31, 2009
Hi all:

Without sounding like i'm beating a dead horse--KUDOS, Danny, for taking the time to put this together. Like many other commenters here, i was skeptical about replacing the HD to my 20" aluminum Imac as it was the first of the newer Imacs that i hadn't touched yet. G5, powerbooks, macbooks are all cake to me...

But my situation is slightly different. I was prompted to change my internal HD after it seemed to have failed out of nowhere (and 2 months after my warranty was up!) I was playing world of warcraft when the machine seemed to have frozen and an open-apple, Alt, escape would not get me to force quit the applications. So a hard restart was in order, but upon restart--the computer couldn't find a start up disk and it wasn't recognizable if i started up as a firewire drive.

I ordered a seagate HD as a replacement and started the process of replacing the drives using your tutorial and getting visual aid from someone who made a video on youtube. IT wasn't as scary as I thought, and the process took me no more than 10 mins to replace.

I reassemble the imac and close everything up, start up the machine, install Leopard, do the updates--all of them--and then continue to install World of Warcraft and do all of their updates.

Now, here's the problem i'm experiencing. The imac restarts fine--looks and works like a beauty--but, whenever the machine's GPU is 'challenged' and heated up (like, after playing WoW for an hour), i start to notice this fuzziness appearing on the screen. it's an interference like when we used to watch TV and our moms would put on the blender--except its not that heavily 'noisy' and it seems to happen gradually; a few lines here and there--but then gets progressively worse with continued use.

it's been very hard to pinpoint this issue as it appeared to have started as a failing HD issue. But now that everythings up and running again, I'm almost pointing towards the fact that it could be a failing Graphics card (I experienced a similar issue with my old G5 where the graphics card was so overheated that before it failed, it would draw up the screen withi crazy geometric shapes and colors. o.O)

So it's very comforting to hear that i may be able to swap the GPU (i'm very patiently waiting that tutorial), but i'm wondering if maybe there's a cable that I unplugged--but didn't replug. or if there's some shielding that i'm over looking that may allow for interference. I'm also hoping that someone else out there has experienced something similar only because its so tricky to explain. I can tell you that all I detached was the camera at the top of the bezel, and the wire that plugged into the motherboard that read the LCD temperature. When preparing to remove the drive(or reinstall it) there were two sets of wires that run on the right side of the imac connecting the LCD to the motherboard. I detached both of those--but reattached them before closeing up the machine... Those were the only things i detached/unplugged during this installation.

Anyone experience anything similar? Anyone know if there's a snapshot of the inside of these newer imacs with some information as to what wires/parts/sections do what?

looking forward to hearing from this community. Thanks in advance!

Re: Screen Fuzziness/ interference?
written by Danny, March 31, 2009

Thank you for sharing your experience with us and congratulations on your success with iMac hard drive upgrade smilies/smiley.gif

I believe in your case the *heat* might be your enemy. Driving GPU to the max for prolonged periods of time will certainly impact the performance of the cooling system, it will also most certainly reduce HDD life and it is possible this is also related to your screen fuzziness issue.

Please let me know if your screen fuzziness is localized at the same place where the HDD is placed inside the machine (upper middle of the screen)?

Also please install iStat widget in order to monitor your iMac temperature readings. When the screen fuzziness appears, quit WoW and open the Dashboard in order and tell us what the readings for HDD, CPU, CPU Heatsink, GPU, GPU Diode, GPU Heatsink and Ambient are?

re: Screen Fuzziness/interference?
written by Migsy, March 31, 2009
Hi Danny,

Thanks for the quick response! I agree that the heat is my demon. The computer is on my desk and has decent ventilation around it. But it does tend to get hot when i'm playign the game and i'm not exactly sure what else I can do to reduce the heat. I may have used the smfancontrol app--but that didnt' really help.
I've used the machine to play WoW for a lil over a year and it crashed maybe 4 times--and graphically locked up maybe twice. One time, after a lock up--i kept hearing this beep beep noise and i couldn't get it to stop unless i took the AC adapter out of the outlet. I Restarted the computer and it was working fine. Initially, I thought this was an error on Apples part--this imac is actually refurbished...but i feel like if it was faulty--it wouldn't have performed so well for a year.

OK, back on topic though. If i recall correctly, it looked like the GPU may have been located at the top-left of the imac, where the HDD may be somewhat more in the center, but the screen fuzziness appears all over the screen. It starts on the upper portion of the screen in a very subtle way, but i noticed the more i use it/the more it gets hot, the more fuzziness i see. Also, when the screen attempts to draw out something in light colors, you can really notice the fuzziness there. I will have to pay more attention to notice if the fuzziness starts within the immediate vicinity of the HDD. Also, I ihave installed Istats widget (which i'll have to reinstall since i've reinitalized the Imac again last night--still has fuzzies!) and I think it took about a 20 degree (c) temp hike before the fuzzies appeared. But I will re-install the widget and i will try to replicate the issue again tonight so that I can include the iStat reports, as well as where the fuzzies start.

More on this when I arrive home from work. Please stand by smilies/cheesy.gif
I have returned!
written by Migsy, April 01, 2009
hello Danny, et al:

I have reinstalled the iStats and began to replicate the problem. I have taken screen shots of the iStats utility upon start up, and then took another screenshot when the graphical stuff started to happen.

Below, should be a link to the screenshots which basically compare the two states. Looks like my GPU gets annoyed and begins to act up once it gains another 25 Degrees. Also, what else I noticed is that this fuzziness happens on the top and bottom portions of the screen. I hadn't noticed that in the middle of the screen. Hopefully the image tag below worked. if not, i will try a hard link to it.


Won't go back together all the way...
written by Jeffrey, April 01, 2009

I just tried this with my new 20" 2009. Everything seemed to go smoothly, but when I tried to put the cover back on the ram slot, it wouldn't go in. I looked, and it seems like the silver part isn't closing far enough down over the case to completely close. I've taken it off and tried several times, but with the same result. Obviously I've screwed up somewhere. Any ideas?

Re: Screen Fuzziness/ interference?
written by Danny, April 01, 2009
Hi there Migsy,

The ultimate question now is when you let the machine cool down - (leave it on, just don't force the GPU) - does the problem go away?


Are iMacs designed for heavy gaming at all?
written by Migsy, April 01, 2009
Good morning ya'll.

Danny, Its definitely an issue that happens after the machine warms up. So, for the first hour of gameplay, its perfectly fine--a flawless screen viewing experience. After an hour or so, then the artifact appear. I could still play thru them--and i'm sure i could use the machine for other tasks while the artifacts are there, but as the machine cools down so does the fuzziness/artifacts.

I am banking on a failing graphics card at this point. smilies/sad.gif Not sure what else to do at this point...
Are iMacs designed for heavy gaming at all?
written by Danny, April 01, 2009
Hi there Migsy,

I was just wondering if this is iMac design flaw (e.g. do other people have the same screen fuzziness experience when driving their GPUs hard) and what are the heat dissipation specs for GPU?

What you should try doing, as a next step, is to install utility such is SMC Fan control and manually set the speed of all three fans to 80-90% of the scale. Your machine will be noisy, however play WoW and see if the screen fuzziness issue reappears - what is your GPU temperature reading at that point? It's a shame that iMac GPUs do not have their own cooling fan, however the theory that we need to put to the test here is if these three other fans will contribute to additional GPU cool down?

Other than that, replacing GPU might not provide the result if iMacs are really not made for extensive gaming (in order to assess this we need to see if other people have the same issue). iMac GPU is a standard MXM graphics card found in most of the modern laptops (being a plug and play card which can be easily replaced), however it is very difficult to find an original Apple GPU MXM card on the market and it will cost you an arm and a leg.

On the other hand, one could install a non-Apple MXM GPU card with even higher performances - such as for example ATI HD 3650 - however it would require graphics KEXT strings modification in order to make the hardware recognized by OS X (similar mod as in making sure the third party graphics cards work in Hackintosh builds - PCs running OS X). This is perhaps one of those cool projects one might consider doing - however they require lots of tech knowledge.

Your other alternative is also to contact Apple support and check with their technicians what do they think of the issue (providing them with particular details, GPU temperature readings, etc).

Finally, an adventurous user might try improving the GPU cooling system in iMacs - for the time being the GPU is cooled only with a passive heat pipe system. Adding a GPU fan or some other crazy approach (water cooling system) might be a cool mod to do as well (however still requiring significant skills and I'm not sure if it will pay off in terms of cost vs benefits).

At this point I would be really interested in finding out if this is happening to other iMac users and if iMac are designed for heavy gaming at all?

Are iMacs designed for heavy gaming at all?
written by Migsy, April 01, 2009
Danny, Great input.

I have to say i've thought the same thing--especially when my g5 tower seemed to have had its Graphics card burn out (it was the top of the line card for the G5's--nvidia 1600xt maybe?) and that was under moderate-heavy game play. For the design for a tower--mysterious. But in the case of portables or compact designs--was it even well thought out?

The first thing i noticed about these laptops and imacs (or compact computing systems) is that they tend to get very hot. My imac and macbook pro can both fry an egg if i've used them to play WoW for 2 hours. But I also figured that these things would be taken into consideration by the engineers who though of putting these things into tinier packages. /shrug

But the reasoning for me leaving this comment was to see if any other person has experienced this. The imac--though working flawlessly for over a year until this blip--is a refurbished machine I bought from Apple. While these problems did not happen until recently, i'm wondering if they can be attributed to the machine being refurbished? Was this the initially problem that caused the machine to be refurbished?

I'm not completely sure, but I will give the smc fan control a shot. I had it installed before--and didn't really set the fans to 80-90%--but that was because i was afraid of burning out something else! LOL

More on this a little later. And thanks, Danny, for giving this particularly *interesting* topic some attention and decent advice!

Are iMacs designed for heavy gaming at all?
written by Danny, April 01, 2009
Migsy, can you take a photo of your iMac fuzziness issue and post it here? Thanks! Danny
Imac update v3.0
written by Migsy, April 02, 2009
Hello Danny/ All.

So i've downloaded and set up the smc fan control and set the fans to around 80% scale. That revved up the fans to an average of 3800-4100 rpms. The imac was noticeably louder, though not annoyingly louder, and the machine felt much much cooler. I couldnt' replicate the artifacts.

So i shut off the fans to get the machine to operate as it normally does. And after about 1 hour (and or - a 20 degree increase ) I started to get the artifacts. The only problem is Its very hard to get a shot of it because its very subtle. So a picture from a digi-cam doesn't necessarily grab the artifacts. and as we know, a snapshot from the computer doesn't actually reveal the artifacts. I'm going to have to devote some time to burning this machine up again and seeing if i can get a clear shot of what it is i'm talking about.

Anyone know if there's a windows equivalent to this Smc fan control? Also, how safe is it? would that blow out the fans in sn overclocking-kind-of-way?


written by Danny, April 02, 2009
Hi there Migsy,

It seems the solution to your problem is to use SMCFanControl. You'll need to experimentally determine the settings for the fans, if the trick worked while running fans at 3000-4000rpm, then work your way down and decrease rpms until you find the optimal speed that cools down your GPU without showing the screen artifacts. I'm sure it will take you couple of days and some patience in order to determine the optimal fan speeds in your case.

Running fans that high won't damage your machine, but you're certainly shortening the life span of those fans - hence the need to have them running at a lower speed (you'll experimentally determine) that solves your issue. If you look at it the long term, even if you burn out the fans (and I believe it will take couple years to truly do that), replacing them is way less costly then replacing the GPU.

Another approach is to leave the fans running normally (at their factory setting) and rev them up just before you play games (also revert the settings once you're done playing).

Good luck!

Let me add more thanks!!!!
written by Dave, April 04, 2009
"Invalid node structure" error on my original 250GB HD; Apple wanted $400 to put in an identical drive, and they didn't think they could do any data recovery. $100 for Disk Warrior to get the data off the failing drive and then finding this guide was like finding the holy grail. Hadn't swapped out an internal HD in almost 10 years, but using this guide, the installation of my new 1TB drive was easier than that old Gateway computer of the last decade. Since the data recovery folks were talking $1,000-3,000, I figure I'm a couple of grand ahead right now.

Thanks ever so much for not only a terrific guide, but also the constant updates and tips. Really good stuff. And my 7-year old daughter was impressed to see the inside of the iMac, too!
Thank You!...
written by Chris, April 14, 2009
I had the "no" symbol and the "gray folder with the ? mark" on it and that was the end of my original 320GB HD, only 13 months after I bought it. Fortunately I had lots of backups with Time Machine.

I bought and installed a new 1TB HD from Western Digital, and had it back up and running in two hours, looking just like it did before the drive died.

The entire operation was not difficult at all. I took my time and it paid off. The HD carrier is a "quick release" type of set up, not at all hard to figure out how to remove. I pushed the drive itself towards the "pins" side of the mounting bracket, then pushed on the black plastic snap in lock and the drive popped right out. I did all of this without taking the screen out, just levering it up some with one hand and removing the drive with the other.

Thanks again for your advice on the replacement of the HD. I love do-it-yourself computer fixing, proving once again that old labeling of "No user serviceable parts inside".....dead wrong! LOL smilies/smiley.gif

iMac Drive Noise
written by Jada855, April 18, 2009
Excellent tutorial! I did have a few questions about drive noise coming from the iMac. I originally wanted to upgrade because of a gargling noise coming from my iMac with the default 250GB drive so I installed a segate barracuda 1TB drive to find out the gargling noise was still there but a bit quiter when data was been accessed I also noticed a constant humming coming from the drive.

I put back the original Western Digital drive and no humming sound. I took back the seagate barracuda and got a western digital black caviar 1TB drive installed to find a loud gargling noise when data is accessed and also humming coming from the drive if you touch the base of the iMac you can feel the vibration funny thing is if I lift the iMac in the air the humming stops open to any ideas suggestions. Is it possible the temp sensor wires on the hard drive could be causing some type of interferance? Thanks again for this awesome tutorial.
iMac Drive Noise
written by Jada855, April 18, 2009
Excellent tutorial! I did have a few questions about drive noise coming from the iMac. I originally wanted to upgrade because of a gargling noise coming from my iMac with the default 250GB drive so I installed a segate barracuda 1TB drive to find out the gargling noise was still there but a bit quiter when data was been accessed I also noticed a constant humming coming from the drive.

I put back the original Western Digital drive and no humming sound. I took back the seagate barracuda and got a western digital black caviar 1TB drive installed to find a loud gargling noise when data is accessed and also humming coming from the drive if you touch the base of the iMac you can feel the vibration funny thing is if I lift the iMac in the air the humming stops open to any ideas suggestions. Is it possible the temp sensor wires on the hard drive could be causing some type of interferance? Thanks again for this awesome tutorial.
iMac Drive Noise
written by Danny, April 18, 2009
Hi Jada855,

Please reference the earlier post on the hdd noise above "Noisy HDD as of January 17, 2009".

The drive has to produce a noise, it just depends on what do you consider to be normal or loud. There are three things you need to look into that can relate to this problem:

1. The drive type itself. Some are louder than others. Also, what is your personal criteria of "loud"(?). The absolutely quiet drive (in comparison with all others) is WD Green 1 TB mentioned at the top of this page (however spinning at a lower 5400 RPMs and has a bit slower performance than regular hard drives spinning at 7400 RPM).

I've personally had a HDD noise problem in my other computer (its a PC Hackintosh) and I've had a Seagate 1 TB and Seagate 1.5 TB installed. The 1 TB drive was way much noisier than 1.5 TB drive (I suppose older vs newer technology), although the same manufacturer. Nothing was wrong with the drives, it is just a fact that some drives are louder than the others.

If the minimum noise is your criteria, the only drive I can recommend that will meet the noise criteria of the most demanding is 1 TB WD Green.

2. In terms of the installation, wires or temp sensor are certainly not affecting the noise. The only relevant part are the HDD rubber shocks as in the earlier mentioned post (if there is a problem with them, the vibrations are being carried to iMac's metallic bezel).

3. Now, here is a funny thing - perhaps there is nothing wrong with your iMac or the hard drive, but your desk is picking up the resonance (influence of the external environment in relationship with the normal drive spinning resonance, hence amplifying the drive's native resonance). I've had an external HDD sitting on my desk (1 TB WD My Book Studio with Firewire 800) that was normally vibrating, however while in direct contact with the desk surface, it had its resonance amplified and produced a relatively loud humming noise. Since then I've put my external hard drive an a cheap standard mouse pad, and it solved all issues - no resonance is being transferred or amplified as it is not in direct contact with the desk's surface. I'm mentioning this as you've said when you lift up your iMac in the air, the noise stops. Well, perhaps its a $5 mouse pad solution in your case too smilies/smiley.gif It would be very interesting to know if this solved your issue smilies/smiley.gif

Good luck,


PS: In terms of hard drives, I believe that 1.5 TB Seagate is the best deal for the money vs performance and the noise. I have 6 of these drives in all of my systems, and I'm very happy with them. Highly recommended!
iMac Drive Noise
written by Jada855, April 18, 2009
Hello Again Danny,

First off thanks so much for you reply it helped a great deal! I am a designer and my original reason for trying this was the noise coming from the default WD drive inside the iMac. I have tried the following drives WD Black Caviar 1TB 32mb cache was the loudest of them all with a grinding noise for everything even window resizing. I also tried the seagate barracuda 1TB this drive was a bit quieter but I could still hear a grinding noise when data was being accessed. Upside about the segate 1TB it was SUPER FAST! like my desktop loaded fully 5 seconds fast I was really impressed but the noise was still and annoyance I exchanded this drive for the WD Black Caviar but it was a let down things were starting to look pretty bad at this point one last try enter your suggestion seagate barracuda 1.5 TB unpack open iMac install did a clean leopard install all was ready testing windows opening,applications etc not a sound tears of joy began to spread this could be it currently now doing a time machine restore and really put the data accessing to test I will let you know how it goes.

As for the humming coming from the iMac I beleive it's caused by the terabyte drives with the original 250GB no humming at all so it maybe safe to say I did not tweak anything when opening. But again I did what you suggested put a small pad between the desk and iMac and no humming noise. It seemed like the humming noise was going right through the desk once again thanks for the help on that part. If all is quiet after time machine restore that would be awesome. I may try and tackle the GPU next once the tutorial is complete I would not mind a 256 or 512 card smilies/smiley.gif thanks again for the help and reply much appreciated.
iMac Drive Noise
written by Danny, April 18, 2009
Hi Jada855 - I'm glad that 1.5 TB Seagate and the small pad resolved your issue. Enjoy! Danny
Watch that temp sensor.
written by Pinky, April 19, 2009
If the temperature sensor is damaged, that can result in a lot of additional fan noise. I had a drive die in a late white plastic iMac and the sensor went bad somehow. I got it back and it sounded like a plane waiting to take off. The noise was impressive for its volume...

I got a replacement and all was well.

I found this post while contemplating a DIY drive upgrade and will put more thought into it before I risk my system and Applecare. I did however wonder how to get the blasted thing open. Who knew that the glass was only held on by magnets... Something so simple, so elegant...
Thanks Danny - you're a life-saver
written by Hanna, April 30, 2009
Hi Danny, I just wanted to leave you a quick note and thank you for the excellent tutorial. My HD died yesterday, so I read your guide and went out and bought myself a 1.5TB Seagate Barracuda, a set of Torx screwdrivers, and some bathroom suction cups. Got some extra RAM while I was at it.

I followed your tutorial to the letter, and it worked out brilliantly. It took me less than a half hour to take it apart, install the drive, and put it back together. I had a full Time Machine backup, so I'm currently in the process of restoring my system.

Without your guide, I wouldn't have had a clue how to do this. So thank you, truly. You've made this Apple fangirl and her iMac really really happy.

Optical drive replacement
written by E. Jones, May 07, 2009
You mentioned in the body of replies that you have replaced the optical drive in the AL iMac. I'm looking for a how-to to replace the optical drive. Any chance you'd be posting some info about how to do it?

Some Questions before I start
written by fatalfred, May 11, 2009
Im about to finally do this awesome DIY. Bought everything I needed today, but before I start. I have some questions (Maybe a stupid questions) smilies/smiley.gif
But anyways....
1) I have a 320GB HD on my iMac at the moment and a 1 TB seagate HD which needs Firmware update on an external. I also bought I Seagate 1.5 TB HD (not affected model) and was wondering if I should replace my current 320 with the 1 TB and update the firmware or use my unaffected 1.5 TB.

2) When restoring, should I use my original install disks which has Tiger and a separate Leopard Disk or will I be able to use my friends newer install disks which he got with his new Macbook Pro?

Thanks in advance!

RE: Some Questions before I start
written by Danny, May 11, 2009
Hi there Fred,

1) The decision is really yours. Do you have any issues with 1TB external drive? The Seagate drive issue with old firmwares is really one in thousands that you'll have problems (data loss in very rare occasions) - so the question is do you really have problems with the external drive? do you have any critical data on the external drive that would require extra precaution and firmware upgrade?

In my personal opinion, I think it would be prudent to put the 1.5 TB in your iMac (also because this is a quieter drive than 1 TB Seagate and a newer technology), and in case you have problems with your external 1TB, it shouldn't be too difficult to find a friend with a PC to upgrade the firmware (and also if you experience problems with it - if not you just might leave it as it is)

2) This is my experience on this one - I've tried using newer Leopard 10.5 discs on an iMac 2007 and it didn't work - it detected the machine type and said that the discs are not compatible with this model. On the other hand the new discs worked on iMac 2008. So you should try with the new discs and see how it works out for you. You can always execute the plan B) installing Tiger and then Leo. Also, if you have Leo upgrade disk - the one you used to upgrade Tiger - then you are all set, because if you look at some of the early posts above, you can install straight away (without installing Tiger first) from the Leo upgrade disc, however the trick is to tell it not to do the install, but a recovery from the Time Machine -- when you get to that screen, just click back and do a normal install (this way the upgrade disc will think it is restoring a previous install, rather than installing from scratch and looking for Tiger).

Please let us know how it worked out for you!

Take care,

written by fatalfred, May 11, 2009
Thanks for the quick reply Danny!

I am in the process of Backing up at the moment using Super Duper not Time Machine. Any experience with restoring from Super Duper.
the speediest
written by gnuga, May 12, 2009
Powered by the latest Intel Dual Core processor, 2.66 GHz Intel Core 2 Duo processor and 4GB of the latest industry DDR3 RAM (max. of 8 GB), Apple iMac MB418LL/A 24-Inch Desktop is the speediest machine from Apple.
Need help with HD replacement
written by Vince , May 12, 2009
Hey guys I have a 24" Imac with a failing drive and need help installing the new one I bought (640gb western digital caviar blue). Does anyone know anybody in the Boca or Fort lauderdale area who can help me out with this for a small fee?

I have been told to stay away from geek squad
Seagate 7200.12 1TB
written by Kired, May 13, 2009
Just finished installing a Seagate 1TB 7200.12 drive in my 2007 24" iMac. So far so good! Thanks for posting this tutorial it made things much much easier. I'll post if I run across any issues with these new Seagate drives.
XBench Results for Segate 7200.12 1TB in 2007 24" iMac
written by Kired, May 13, 2009
Forgot to add this to my other post for those who are interested:

System Info
Xbench Version1.3
System Version10.5.6 (9G55)
Physical RAM4096 MB
Drive TypeST31000528AS
Disk Test58.23
Uncached Write203.16124.74 MB/sec [4K blocks]
Uncached Write203.79115.31 MB/sec [256K blocks]
Uncached Read96.4028.21 MB/sec [4K blocks]
Uncached Read242.46121.86 MB/sec [256K blocks]
Uncached Write10.451.11 MB/sec [4K blocks]
Uncached Write283.3790.72 MB/sec [256K blocks]
Uncached Read116.670.83 MB/sec [4K blocks]
Uncached Read188.2634.93 MB/sec [256K blocks]

It is also sitting around 50c temp wise while copying some data back too it.
written by Vince, May 14, 2009
Ok here we go. About 2 months ago my computer crashed and I got the white screen. Every thought it was a hardware problem with the hard drive. Finally I took it to genius bar (no warranty) and they fixed it with Disk Warrior. I then bought a Lacie 1TB external so that I could back up my system just in case they didn't fix it for good.

After I set up the external hard drive, I partitioned it. Half for time machine the other half for my ps3 (movies, music, photos) and everything worked great. I erased and re installed leopard just in case and then booted with time machine and everything restored and was running better than ever.

Now 2 weeks ago my iMac crashed again, (white screen with ? folder). I unplugged everything and went to bed. This morning it started up so I hooked up my external (which wasn't and hasn't been hooked up to the iMac since initial back-up) in order to back up all my new stuff, however I noticed that the iMac didn't recognize the time machine partition, only the PS3 partition. I ran disk utility and it could not repair the time machine partition which was now named disk01 or something like that. A few minutes later it froze and crashed.

any advice?

I bought a new internal (640 WD Caviar Blue) but have not installed it yet.
Re: Crashing Problem
written by Danny, May 14, 2009
Hi there Vince,

From what you are saying it sounds your internal hard drive is failing. While Disk Warrior might have seem to repair it, this software utility (nor any other software as a matter of fact) can repair a failing disk. HDDs are mechanical devices and sooner or later they will fail (more info on HDD failures). When they start to fail bad sectors start showing up (irreparable areas on the disk's data platter). What Disk Warrior (and other utilities) do is they mark these bad sectors as unusable and they move data around (Disk Rebuilding process). Therefore, it might seem disk is software repaired, however its mechanical failures are not and disk has just been "patched up" with software (being only a *temporary* solution to the problem). Once bad sectors (mechanical failures) start showing up on the disk, they are very likely to spread very fast causing additional data damage - which might very well explain your second HDD crash in two weeks.

What I would recommend is that you install your new HDD in your iMac and install Leo OS X. Do not worry about not being able to access your backup at the boot or DVD install time, just do an install without Time Machine recovery. Make sure Leo is running. Then you can start Migration Assistant (located in Applications then Utilities) and recover your data from the external drive (it will provide you with Time Machine or external HDD drive data migration option) - I'm sure that at this point the system will be able to recognize the appropriate partition.

Save the old drive - just in case your data backup from the external drive doesn't work. You can attempt to reconnect your old failing drive through an external enclosure and run DiskWarrior to try to fix it and use Migration Assistant to import data onto the new hard drive.

Please let us know how it worked out for you.

RE: Crashing problem
written by Vince, May 15, 2009
Thanks Danny. I will do that as soon as I can. A couple questions though if you dont mind.

How hard is this (installing HD) to do it myself? The only thing I am nervous about is the LCD screen (dead pixels, dust etc..)

Also, are you confident that migration assistant will find the TM partition even though it came up bad when I ran disk utility on it?

Even if it did find it shouldn't I stay away from putting it on the new internal since it messed up my external, won't it mess up my new internal??

What do you think? Thanks
RE: Crashing problem
written by Danny, May 15, 2009

1. Your decision if you'd like to proceed with the upgrade very much depends on your previous experience and skill set - for some people this is a breeze, for others its hard to do. DIY is available at this page, many readers have reported successful installs, however you're fully responsible for the consequences yourself in case something goes wrong. On the brighter side, if you are very very careful in handling the display and other components, the likely hood of everything going well is pretty high. If in doubt, perhaps it's a good idea to have a friend assist you, and finally you might opt to hire professional assistance locally.

2. It was only my best guess, that's why I've recommended you to keep the old drive.

3. This shouldn't be an issue in your case as the reason for "messing up" is very much different than what might really "mess up" the current Leo installation - and that is various erroneous settings in "Preferences" folder and other system files. If in doubt, when using Migration Assistant don't tell it to transfer all user settings, just files, and you should be 100% OK.

Good luck.

Thanks so much!
written by Mac, May 15, 2009
Hey, I have a 20" Core 2 Duo that I was given by a friend. It wouldn't start up past just turning on. I would get the question mark in the folder icon. After purchasing a new HD and using your install instructions it works great!!!!!. A lot of it I could have figured out but I probably would have broken a few things first. First time's a charm. Now I can do it again.

Thanks to the good suggestions from the responders as they came in handy too.

Thanks again!

Temperature sensor??
written by Vince, May 16, 2009
Hey guys I just got done doing the install and I am alittle scared. I am installing mac os x right now but I have a question with the Temp sensor. I noticed on the original internal HD there was a Thermistor clip for the sensor to go in. However I did not take that clip off. I just placed the sensor on the new drive and put the adhesive over it. Is that ok?? Was I suppose to do that? or is something going to go wrong now??
Re: Temperature sensor
written by Danny, May 16, 2009
You should be OK, as long as the sensor is securely affixed to the drive (the function of the clip was to make sure of this). Hopefully you've glued it well smilies/smiley.gif

Use iStat menus to get the readout of the HDD temp. If its within the standard range (~55C or 130F) it should indicate the temp. sensor is working OK.

written by Vince, May 17, 2009
Hey Danny, I tried the migration assistant and it could not find the time machine partition. When I run disk utility on the TM partition I get " invalid B-tree node size". Is there anyway to fix this partition and get my stuff back???
imac no dvd drive
written by will, May 18, 2009
I have a alum 20" imac 2007 2 ghz.
I'am having optical dvd drive problems the finder doesn't see it.nor does toast.
I put in a dvd and finder nor toast will not see it .
In toast it says no drive .
Please tell me what need to do.
Optical Drive help
written by emi, May 19, 2009
Hi Danny,
Thank You so much for the great tutorial! You are the MAN!!
I have a 20" 2008 iMac that desperately needs the optical drive replaced.
You gave some great info already about this in the discussion above but just fell short of what I need to attempt the replacement. If possible, please post or send me the pics you took and info of what I need to replace the optical drive. I'm not sure of all those connections you talked about above.
Thank you, Thank you Thank you!!! :-)
Partitioning a 1,5TB disk
written by Bob, May 20, 2009
Hi, I've just bought the Seagate Barracuda 1,5TB (ST31500341AS) and will install it during the weekend. I have a question about how I should partition the disk. Do I use just one big partition of 1,5TB or do I create 1 partition for the OS and another partition for data? In the last case, do I move the users home folder to the second partition?

Any advice on this?

Thanks, Bob.
RE: Partitioning a 1.5TB disk
written by Danny, May 20, 2009
You should be fine with a single partition only. Splitting partitions to OS and Data is something people would usually do on a PC - in case when (not if) your Windows partition crashes you still have your data saved on the data partition - not necessary for Mac. The whole deal with data protection for Mac is to have an external hard drive for automated Time Machine backups.

Re: Replacing iMac Optical DVD-RW
written by Danny, May 20, 2009
For you guys asking on how to replace the optical drive, here is a quick tutorial:

You need to take your iMac apart - same as with the HDD upgrade - however in addition you need to take apart the right hand side speaker and cooling fan assembly

Then you'll arrive to something like this:

I've marked the cable leading to DVD-RW, unplug, unscrew, install the new drive, and follow the reverse logic to close everything up.

Replacement optical DVD-RW going into iMacs are:

UJ 875

UJ 857

Good luck!

RE: Partitioning a 1.5TB disk
written by Bob, May 20, 2009
Hi Danny,

thanks a lot for the info. I'll create a single partition on my 1.5TB disk ... indeed I switched from a PC to a Mac and there I used separate partitions for the OS and data. In case of a crash I could easily put back a ghost image.

No experience yet with time machine ... I'll set it up now to experiment with it.

Thanks again and continue the good work,

Re: Time Machine
written by Danny, May 20, 2009
Hi Bob,

I was a switcher as well, now it seems so long ago smilies/smiley.gif Time Machine is like an automated ghost image - it does everything automatically for you, no need to manually start it up and wait for it as with PCs - it just runs in the background without you even noticing. If you have a crash - and I've never had a Mac crash, the only reason I was recovering files from Time Machine was when swapping hard drives - there is Migration Assistant in Applications, Utilities - it allows for recovery of Time Machine data with a single click - almost the same as with the ghost image - just built into the OS. The Time Machine is also unbelievably useful when you delete or lose files you need - just click on the Time Machine icon at the dock and you can recover your files for as long in the past as there was hard disk storage...

In order for Time Machine to work you need an external hard drive. You can go with USB (480 mpbs) or Firewire 400 or 800 (mpbs) -- so it is really a choice between USB or Firewire 800 (as firewire 400 is the same speed as USB, just more expensive). I myself have Western Digital My Book Studio Edition 1 TB - and I'm using it with Firewire 800 port - it is so much faster than an USB drive - works like a charm.

Good luck exploring your new Mac and welcome to the Mac community smilies/smiley.gif

Thanks for the Optical Info!
written by Emi, May 24, 2009

Many thanks again for replying to my optical question so quickly, and posting the pics! smilies/smiley.gif
Now I have the incentive to do this and plan to try this as soon as I can find a replacement drive.

Hope this also helped some others too! You are the MAN!!
I'll let you know the outcome...thanks!

written by fatalfred, May 25, 2009
Sorry for late update....I just didn't know what to do with over a terabyte of free space! smilies/cheesy.gif

Seriously, Big thanks Danny, and to all guys & gals who contributed to this DIY. Your tips, comments and experiences were invaluable. I am now official upgraded!
So for all, who like me were doubting that you could do it yourself, believe me you can cos I am the least tech- savvy person I know.

Just somethings that I'd to share:
I upgrade my 2007 iMac with a 1.5TB seagate drive.
Used 2 bathroom suction thingys.
I didn't disconnect all connectors, just the first 2 and flipped the screen over and leaned it on the wall. (the third connector was giving me a hard time so I left it)
On reinstalling, I tried to re-install with the new install discs from a 15in MacBook Pro, but it wouldnt accept them, so had to use the originals which came with the machine.

Other than that, it was a snap!

Thanks again!!!!

Till next the DIY

Optical Face Plate
written by Emi, May 29, 2009
Hi Danny,

I just received the UJ-875 optical replacement drive for my iMac 20" 2008 and to my surprise it has a black face plate, button, and LED that I didn't expect. I was all ready to do the surgery...LOL.

Can I still use this model and if so, how do I remove the faceplate?
Any info would be much appreciated.

Optical Plate Just Popped Off
written by Emi, May 29, 2009
Hi Danny,
Fiddling around with the face plate, I was able to easily pop it off with my fingernail...LOL
Nothing much holding it on but 6 plastic grabs that luckily didn't bread off. Looks like I'm back in business. :-)

Thanks much, and I'll let'cha know how it all turned out.
You guys rock!
written by ndtwc, June 01, 2009
I've never thought of those photographs can be that useful until I'm really getting my hands dirty! Big thanks to Danny and all commenters for building up such a great guide!

My old hard drive in my early 2008 24" iMac got problems for quite some time already, and the warranty is over, and yeah I don't have AppleCare! Now with this guide I've successful installed a new Seagate Barracuda 1.5TB hard drive in just about an hour!

One more thing, for step 6, the alternative way is definitely better, at least for me...

And I didn't unplug the iSight cable, and also the third cable of the display, I just flipped the silver frame and the entire LCD screen over.

Big big thanks again to all contributors of this guide! You guys and gals rock!
Thank you Thank you Thank you!!!
written by Jon, June 06, 2009
Thank you for taking the time to write up this tutorial. My hard drive crashed less than 1month after my warranty expired and I am in the process of launching a site for a client. I thought I was SOL but I was able to get the drive replaced on my own and I'm waiting for time machine to restore.
CPU Fan issues?
written by Dave, June 08, 2009
First off, thanks so much for such a detailed guide! I purchased an new 2008 imac on clearance about a month ago. I replaced the factory hard drive on a 24 (200smilies/cool.gif imac right out of the box, with a WD Black 1TB drive. Everything was going so well, until a few days ago, when I noticed the iStat reading for the CPU Fan was 000RPM.... I tried an SMC Reset and a PMU Reset to no avail. Even tried "Fan Control" and SMC Fan Control... nothing can startup the CPU fan. Couldn't find any similar @ Apple support or via Google. Anyone have similar issues after a hard drive upgrade?

Has anyone who has replaced their HD try to submit their imac to apple for repair? Would they accept it under Apple Care? I was told by one of the Apple retail staff that for the factory warranty to be applied, other than ram, the imac needs to have all its original factory parts. Any thoughts?
RAM 667 versus 800
written by Don Borleis, June 10, 2009

Great stuff here. I have a llate model 2007 24 Imac. I bought it in 2008 but am assuming it is a late 2007 becase my 2 RAM cards ar 1G each at 667. my question is can I repleace these with 2 2G 800s ?
RAM 6700 versus 8000
written by Don Borleis, June 10, 2009
a little more info- I have a late 2007 2.8 GHz According this this website:

http://eshop.macsales.com/item/Other World Computing/5300DDR2S6GP/

They say I can go up to 6 GM (4 2) Is this correct? even thoug I have 667 can I use 800 ?
Thanks for this!
written by Nathan Nitzky, June 14, 2009
I came across this article several months ago and contemplated increasing my internal HDD in my '07 24" iMac from the 320GB, but never got around to it. Yesterday my HDD died and forced the issue. I went to Frys and bought the WD Black 1TB. With this guide and my Time Machine backup to restore with the Migration Assistant, I was back up and running in just a few hours with virtually nothing lost.... Awesome!!! I am now a firm believer in Time Machine.... Only issue was that my password didn't work on restart. Had to boot from the CD and use the password utility to reset. Everything fine now- THANKS A MILLION!!!!
written by Brent Jackson, June 15, 2009
So I went to the Apple store thinking I could just upgrade my drive in iMac from 2007. Sadly, they said it can't be done. They are not built to be upgraded as far as hard drive is concerned. So they pretty much said I was stuck with it, even though I'm out of space.

So I found this post, followed directions, and within 1/2 hour I have a new Terabyte iMac. AWESOME!
smcFanControl vs. iStat Menus HD Temp reading
written by MoabBC, June 16, 2009
I dumbluckily bought an external backup drive and turned on Time Machine about 3 weeks before my original HD died. First HD failure in 12 years of apple ownership. My iMac G3 is still humming along downstairs serving up FTP and DVD's for my kids. Never a day's worry with that old mac. I always back up important stuff but never had a "backup system" in place at home. The good luck of having Time Machine running far exceeded the bad luck of HD failure. Time Machine is sweet.

This guide is fantastic. Pulled off an HD replacement in 30 min. Didn't disconnect any cables. For a non-user modifiable machine, it sure was easy to pull apart and put back together with this guide. With all the plastic iMacs in the past I could never quite put them back together. They never looked quite right after. This aluminum model went back together with the same ease of pulling it apart. Thanks. Wouldn't have dared without this guide.

Replaced my failed WD 500GB with WD Black 1TB. Restore went smooth. The problem I have now is TEMPS and wondering if TEMP played a role in my original HD failure. Machine just feels hot. More so than other iMacs (G5 and other Intels I frequent).

I installed smcFanControl and iStat Menues. They display different TEMP readings for the HD. Whats this all about? smcFanContorl says 51C. iStat Menu says 60C. What temp sensor is smcFanContorl using? None of the temps in iStat Menu read 51C. I can't tell where the smcFanContorl temp readings are coming from. One of the readings has to be wrong.

I tend to believe the 60C. Should my WD Black 1TB HD be running at 60C all the time? I installed last week and it runs at 60C pretty much no matter what I am doing on my machine. Says 61C right now. That is hot! smcFanControl doesn't seem to cool it down. I worry about fan failure running it at high RPM. Should I worry about fan failure?

Should I expect this new HD to fail because of the heat? Or is it just an over achieving, high performance super disk that likes to run at higher temps? It was fun digging into the iMac and fixing it but I don't really want to do it again.
Re: smcFanControl vs. iStat Menus HD Temp reading
written by Danny, June 16, 2009
Hi there,

One of the sensors is measuring temperature external to the drive (that is the sensor you've glued onto the drive) and the other sensor is internal within the drive itself. Therefore, I believe that the external temperature of your drive is 51C and the drive's internal temp is 61C. That is hot! It should also be interesting to see what is your environment temperature like. Most of the drives specify 60C as the upper max. operational temperature. The solution is to rev the fans higher to compensate with additional cooling. Sure, you can run them down, however in couple of years, so I wouldn't be that much worried about it. Another alternative if you really have HDD temp problems is to go with the WD Green drive which produces the lowest temp of them all. Other than that, just make sure you use that Time Machine of yours smilies/smiley.gif

All the best,

High FAN rpm
written by panrobal, June 19, 2009
Hi Guys!

Has anyone experienced High HD Fan RPM after upgrading?
In iStat Pro I see that the HD has only 34 deg. Celsius but the Fan runs at 5500 rpm!
I run
The optical drive fan runs at 4600 rpm and CPU Fan at 3500 rpm.
Maybe I've reattached the temperature sensor into the wrong place? But there was a spot right there on the drive with circles and and degree mark so it should be ok..

Any ideas?

BTW I ran a Mid-2007 iMac 20" with 2.4 GHz CPU and standard 2GB of RAM. I replaced the original drive (because it failed) with a Seagate Barracuda 500 GB ST3500410AS - unfortunately higher capacities are still very expensive in my country.

High FAN rpm
written by Danny, June 19, 2009
Hi Max,

Thanks for writing. It actually happened to me - in my case I've had a fan connector unplugged. Most likely you've forgot to plug something back in - meaning you'll most likely need to go into your computer again and verify all connectors and cables are hooked up where they're supposed to be.

High Fan rpm
written by panrobal, June 20, 2009
Hi Danny,

Thanks for your quick response and of course for the amazing article.
Thanks to you opening an iMac has become a pretty simple task. I've already opened it today and reattached the HD temperature sensor in a different location but still the fan runs like crazy.

As you wrote in one of your updates I managed to replace the HD without removing the display - I used another pair of hands to hold it for me and just detached the two connectors on the back of the display. Is it possible that those connectors below the monitor cause the fan to run so fast if they are attached inproperly - you didn't exactly specify how those should be attached and I didn't remember that after detaching them. But the display works fine - so I guess the mistake isn't here..

This time I'll remove the display and take a look if there's nothing missing - I hope it will finally work. Otherwise I'll have to manage with the fan running so fast (although I think it might shorten its life a lot)..

LCD temperature sensor - literally screwed up
written by panrobal, June 20, 2009
Hi Guys,

Finally I know what caused the fans running so fast - a screw going through the cable which is attached to the LCD temperature sensor. I realized that after completely removing the display I only hope that it will work with the cable somewhat damaged.. Or maybe there is a way to have that cable replaced? I'd appreciate any help.

I pity that I haven't read all the comments before replacing the drive because Salmacis had the same problem.. Well learn from our mistakes guys! smilies/cry.gif

Temp sensor cable
written by Danny, June 20, 2009

You should be able to fix the temp sensor cable with some soldering, or just take the cable to any electronics repair shop and ask them to solder it for you -- should work good as new.

Temp sensor cable
written by panrobal, June 24, 2009
Hi Danny,

Thanks for all the help. After removing the screw from the temp sensor cable the computer is running fine - more than that actually smilies/smiley.gif
I'll take your advice on taking the cable to an electronic repair shop for soldering.
Again help for your help and great tips.

Best regards,
Dont remove the 3rd monitor cable! Too difficult.
written by stu, June 29, 2009
Prop up the TFT panel against a wall with some foam packing in between. Don't worry it will stretch far enough without pulling too much.

Otherwise, well done mate. EXCELLENT GUIDE.
Duo upgrade
written by Harold, June 29, 2009
Hello Danny,

This evening me and a friend of mine installed two 1.5 TB seagate drive's in a 20 and 24 inch imac from 2008. We found out that there is a difference in between the power cable of the 24 and the 20 inch screen.
The 20 inch is easier with the four connectors on the right side as the 24 inch model has only one flat cable on the left side. We did not disconnect this one.

After a time machine recovery everything runs perfect.

Thanx again for the great DIY.

Harold and Richard smilies/smiley.gif
my two cents
written by Thierry, July 02, 2009
Very helpful guide !
I just replaced my hard drive after a crash… Thanks a lot ! smilies/wink.gif

My two cents :

1- On my iMac (beginning 200smilies/cool.gif there are 2x2 connectors behind the screen at the right side (middle and top) instead of the one you describe in the top left corner ( Step 4 )

2- Be aware of the two little screw for the screen connector at the bottom right side (Step 3) when you want to replace these. As they are very small (and if like me you have big fingers…smilies/wink.gif you can loose them in you iMac. So, you can touch one of the magnet on the front panel with your screwdriver. You have now a magnetic screwdriver for few minutes smilies/smiley.gif
Have fun !
Replaced 2007 IMac hard drive with 1.5T drive
written by T2, July 03, 2009
Perfect instructions from your site. The hardest part was keeping the dust off the glass once trying to replace it. Also, time machine restore worked like a champ. Thank you for this site.
Nice writeup
written by gb, July 14, 2009
There's more than enough info here in your tutorial; it's incredibly helpful. Put a 1TB fujitsu in my sister's iMac today. Only used one suction cup to pull a corner off and plucked the rest off by hand. Never disconnected anything but the HD thermometer. I kept the display propped up with a small water bottle like the hood of a car and the swap went really smoothly; about 20 minutes total. Of course the OS install and software updates took hours and hours ^_^
Tamper Seals
written by Shon, July 15, 2009
I was just wondering if there were any tamper seals that have to be broken.
Tamper Seals
written by Danny, July 15, 2009
Shon, no there are no tamper seals to be broken. Good luck!
CPU fan running at constant high speed
written by Derek, July 20, 2009
So I did everything the guide says (upgraded to a 1.5TB drive and 4 gigs of ram on my 24" aluminum iMac (May 200smilies/cool.gif), but now the CPU fan runs at full blast whenever I turn on the system, and stays that way. Pretty sure it's the cpu fan--whatever one is immediately next to the left speaker.

I've reset the smc to no avail. Everything appears to be plugged in properly.

Does anyone have any suggestions?
Fans running at max
written by Danny, July 20, 2009
Hi Derek,

In order for one of the fans to run at max., you must have not plugged back (or properly) one of the cables. If all seems plugged in, make sure they are all the way down inside a connector. You need to go inside your iMac again and you can reference pictures from this guide to check where each of the cables is going to. As there is no reading from one of the sensors, it provides a false reading to the logic board who believes your iMac is hot on fire, and as a consequence fans are screaming aloud smilies/smiley.gif

written by Derek, July 20, 2009
Wow, thanks for the quick response!

Do you know which cable it likely is? I know it's the CPU fan in some way, because when I unplugged it and turn the Mac on, I don't hear anything. The funny thing is, I didn't mess with those cables in any way (at least to my knowledge). I only unplugged the LCD power cable which is near them. Perhaps something got loose in the process but I can't see how.

I'll open 'er up again tomorrow. I'm sort of fed up with the whole thing right now (although I am LOVING how fast my Mac is, and how much space I have! Thanks for the guide!)
Fans running at max
written by Danny, July 20, 2009
Hi again Derek,

One of the readers above had a screw go through a cable when he was closing up the bezel -- you might encounter that kind of scenario in your case too -- or as you say one of the connections just might got loose. In reference to your question which one -- please make sure you check *every* cable, not just the sensor cables (I believe there are three of them), in order to make sure ALL cables are connected properly, especially in the case you suspect some of them got loose (which visually might appear as connected).

written by Derek, July 20, 2009
Well, I'm at a loss. I've checked and rechecked and rechecked every single cable to make sure it's properly connected, and everything seems fine. Any other suggestions before I have to take an out-of-warranty iMac to the Apple Store and pay up the wazoo for it (the very thought of which sickens me)?
Fans running at max
written by Danny, July 20, 2009
Hi Derek,

Thanks for writing back! It's really hard to see what is going on inside your iMac like this, perhaps you can take bunch of photos and upload them to e.g. Flickr and I can have a look...?

written by Derek, July 20, 2009
I'm not too familiar with flickr but I zipped up a bunch of pics and threw them on rapidshare. Hopefully these help in some way. I left them uncompressed.

Fans running at max
written by Danny, July 20, 2009
Hi again Derek,

I've had a look at your photos. Apparently you are missing a connection to the LCD TEMP connector on the lower left hand side of the logic board (next to the left hand side fan). Perhaps this cable is somehow tucked behind the fan or logic board, have a look!

lcd temp connector
written by Derek, July 20, 2009
Yeah that's just from having my monitor detached (it's currently sitting on my bed). Once it's all together, that connector is used.
Fans running at max
written by Danny, July 20, 2009
Well, all other seems in order. You can also check the HDD temp. sensor (e.g. short connected, pins bent?).
Hard drive sensor?
written by Derek, July 20, 2009
Question: is it possible that the hard drive heat sensor is causing the cpu fan to go nuts? I've noticed it has lost quite a bit of its stickiness, so it's possible that it's just barely attached to the hard drive (or maybe even attached in the wrong spot?).
Fans running at max
written by Danny, July 20, 2009
Also, when you install iStats, have a look at all temp. readings - are they all showing up? What are the values for all of them? This might be a way to determine which sensor or cable has a problem in particular!
Fans running at max
written by Danny, July 20, 2009
According to your photos, the placement of your hdd sensor is OK (it should be anywhere on that flat bottom metal part). But how did you handle it, could it perhaps got damaged? I suggest installing iStats to determine temp readings from each sensor and pinpoint the search!
written by Derek, July 20, 2009
Thanks for the help. I'll put the Mac back together and install iStats, and I'll let you know my findings.
iStat Picture
written by Derek, July 20, 2009
Hardware Test
written by Derek, July 20, 2009
I ran the hardware test on the iMac install disc and got this error:

4SNS/1/40000000: TL0P- 130.000
Fans running at max
written by Danny, July 20, 2009
Not sure what that particular error means, I'm sure you'll try to Google it at this point. Did you by any chance take of the logic board completely? The CPU temp sensor is actually on the other side of the logic board... ?
written by Derek, July 20, 2009
Yikes. No, I didn't take out the logic board itself. I didn't even know where to start on that one. It seems like I'd literally have to take the entire thing apart. Although at this point, I'm willing to give it a shot.

Is the sensor just a wire that goes into a connector? Like, is it plausible that it came loose somehow? I haven't been rough with this thing at all, and I don't recall tugging on anything that I shouldn't have, but I'm just curious how likely it is before I gut this thing.
Fans running at max
written by Danny, July 20, 2009
Don't take apart the logic board, I was just wondering! Its just a plug on the other side of the board. I'm sure that's not it because there is no way that could have got loose if you didn't take the entire motherboard off.

I was just Googling that error code and came across a Linux implementation of temperature read out for iMacs, it is definitely an error code pointing to failure of one of the temperature sensors. Now just to figure out which one. At this point I could take a wild guess and assume the HDD sensor is somehow damaged.

Another wild guess, hard drives have an internal temperature sensor as well. This wild guess would be that perhaps something is wrong with your HDD. Which type did you install? Do you have your old HDD drive sitting around? Perhaps another swap?

written by Derek, July 20, 2009
Yeah I've been googling too. I actually found one page (a lot of it was in German) which says it might be the LCD temp sensor, which is entirely possible as I may have dropped the screen on it when putting everything back together (although I'm not sure, this is just a guess). Regardless, I think this is gonna have to go to Apple. Hopefully they'll know what the error code means and can replace whatever needs replacing without breaking the bank. Surely a sensor won't be too expensive? :-

Thanks for all your input though!
Fans running at max
written by Danny, July 20, 2009
Well, we've concluded that during the upgrade process one of the sensors got damaged. Sure the sensor will cost you $2, but the labor charges are the ones to worry about... smilies/smiley.gif Good luck smilies/smiley.gif
Fans running at max
written by Danny, July 20, 2009
Check out this discussion on the Apple forum board on the same issue you have: http://discussions.apple.com/t...ID=9849776

The summary is to use the Temperature Monitor sensor reading software: http://www.bresink.com/osx/0Te...nload.html

This software apparently reads a few more sensors than iStats. Hopefully you'll be able to figure out which sensor you are having problems with!

written by olav, July 20, 2009
My compliments for the guide, I willI am wondering what disk would be best, I figure that I would trade in half a TB for less noise if it was a noticeable difference. Many thanks for your help,

Seagate Barracuda 7200.12 1TB,
Seagate Barracuda 7200.11 1.5TB 32MB,
WD Caviar Green 1.5TB, 5400~7200rpm, 32MB, SATA2
HDD choice
written by Danny, July 20, 2009
Hi Olav,

In terms of the hard drive recommendations for this project, I wouldn't go with Seagate 1TB at this point as it has more than one and a half year old technology (and that is light years in technology).

You won't go wrong with choosing either of the following 1.5 TB hard drives:

- Seagate Barracuda 7200.11 1.5 TB SATA 32 MB, 7200 RPM
- Western Digital WD15EADS Caviar Green 1.5 TB SATA 32 MB, up to 7200 RPM

If we look into technical specifications of these two drives, the following is the comparison between these two drives:

- Sustained transfer rate: WD Green 100 Mb/sec vs Seagate 120 Mb/sec
- Cache: both have 32 MB
- RPM (rotational speed): WD Green - variable (InteliSeek - this is a new technology to reduce power and noise) vs Seagate having continous 7200 RPM
- Power consumption: WD Green - 6W while at full power (read write) whereas Seagate uses 8W while at full power
- Noise levels: WD Green 29DBA at full performance whereas Seagate has 32 DBA at full performance (hence a small difference)
- Operating temperature: WD Green up to 60C vs Seagate also up to 60C
- Manufacturer's warranty: WD Green has 3 years limited warranty vs Seagate 5 years limited warranty

In conclusion, the noise levels between two drives makes a really small difference 29 vs 32 DBA (in favor of WD Green), whereas the power consumption is only 2 Watts between these two drives (in favor of WD Green). Seagate has faster performance for sustainable data transfers - 120mb/sec vs 100mb/sec for WD Green. The major difference is that Seagate extends 5yr limited warranty whereas WD has 3yr warranty only.

If you budget permits it at this time, you might actually consider upgrading your iMac to the latest technology - 2TB hard drives. I would recommend one of the following two models. Price vs warranty are your main choice parameters rather than tech specs as they are pretty close one to another (competition is great) smilies/smiley.gif

- Seagate Barracuda 2 TB drive, 32 Mb cache, 7200 RPM
- WD Green 2 TB drive, 32 Mb cache, up to 7200 RPM

Good luck upgrading! Please let us know how it worked out for you smilies/smiley.gif

written by olav, July 21, 2009
I thought the Seagate Barracuda 7200.12 1TB was actually a new series ( series 12). I will make a choice between the two you advised and will certainly let you know how things went. Or not if I can't get it to work :-)
Seagate series
written by Danny, July 21, 2009
That might be, but Series 12 is available only up to 1 TB and Series 11 up to 1.5 TB, whereas a completely new series was developed by Seagate called LP (Low Power) for 1.5 and 2.0 TB drive (according to www.seagate.com). On the other hand perhaps LP is just a marketing gimmick for new S12 drives smilies/smiley.gif

Hopefully you'll get it up and running - good luck! smilies/smiley.gif
Don't unplug any LCD cables!!!!
written by Alan, July 21, 2009
Guys, it is very easy to swap out the HD without removing the LCD cables. Simply tilt the LCD up on the iSight side about 4". (Your iMac shouoold be laying on its back.) No need to remove the LCD. Then reach in and pull off the temp sensor on the HD. Pull off the two SATA connectors on the left side of the HD. Press the latch and pop out the HD. You needlessly risk messing up one of the LCD connectors by unplugging them. Easier if you have someone to tilt and hold the LCD but I did it myself tilting the LCD with one hand and removing the HD with the other.
Older iMac AL RAM limit/max is 6GB (not 4GB)
written by Jeff Coughlin, July 22, 2009
Thanks for the tutorial. I wrote a similar tutorial for upgrading HDDs in MBPs. I used Carbon Copy Cloner to move over the data from the old HDD to the new one before swapping the drives. I decided to use the same process when upgrading the iMac AL as well.

A couple tips people might find helpful:

- When completely done with everything, go into "System Preferences >> Startup Disk", if your new disk isn't already selected, choose the new drive, and restart (your bootup will be much faster now).

- The original iMac AL (first Core 2 Duo model) can actually go up to 6GB (same with the first MBP Core 2 Duo). I own both (and have upgraded both to 6GB). The reason why the specs on both models say 4GB max is because back then there was no such thing as a 4GB laptop memory module. The nice thing is that Apple tends to go beyond simple specifications and build their machines better than their specs (or so I'm told). Technically you can put up to 8GB of RAM in these models and OS X will register it correctly, but people will tell you that as soon as your machine goes to use any RAM past 6GB, the OS crashes. If you already have 4GB in your iMac AL (2007/2008 model) and want to upgrade to 6GB, you need to only replace one of the chips with a 4GB module (they will be compatible).

Thanks again for the great tutorial/walkthrough. Good job and very helpful!
Optical drive replacement.
written by Fernando alves, July 27, 2009
I've read all the entries on this subject I found them very useful. However, I'm running into a dead end with my iMac 24" aluminum. I got a generic drive from OWC that the computer recognizes as MATSHITA DVD-RAM UJ-875S. The people at OWC assured me that this is the correct replacement part. Does the S after UJ-875 mean anything special? Is it a different part? Secondly: I installed the new drive without any problem, in mechanical terms, but when I try to use it, the CD/DVD will not be "pulled in" by the drive's mechanism, it behaves as if the drive were not connected to power. This will happen no matter how deep I push the disk in. Third: the drive has an ATAPI connection. The original one had also a wire with a black end pegged to its underside. It was held in place by a plastic casing that was covered by a piece of foam that has a sticky side. This wire end is rounded on one side, black in color, and the other side in silvery and flat. I do not recall which side was touching the metal underside of the drive, but I have tried putting it in the two possible positions but always get the same dead end: the drive does not emit any sound nor pulls in the disk. Your hel will be extremely appreciated. H E L P, please.
An update
written by Derek Pugh, July 28, 2009
Hey everyone,

Just thought I'd update in case it will help anyone in the future: turns out it was the LCD temp sensor that needed to be replaced (I must have pinched it at some point). My iMac is now up and running as it should. Only difference I've noticed is the hard drive noise (which was virtually silent before but I can hear it "crunching" data now, not too big a deal but it is a noticeable difference, especially when I have torrents running). Has anyone else experienced this?
written by Danny, July 28, 2009
Hi Derek,

Congrats on resolving your issue with the temp sensor!!! I guess some sound from the drive is normal, especially if you're crunching torrents (it needs to save data every second). For purpose of torrenting, I would actually use some less expensive machine - e.g. installing a Transmission bit torrent client on a NAS storage (i.e. Linux based), or Apple TV (that is if you have any of these). I've actually managed to compile Transmission 1.72 on Apple TV the other day so I do not need to leave my Mac running all the time. Perhaps this would be an interesting article too smilies/smiley.gif

HD Temp
written by Derek Pugh, July 28, 2009
Just a quick question: is 58 degrees celsius (peak, it seems, with Transmission running) anything to worry about? Using a Seagate Barracuda 1.5TB drive.
HDD temperature
written by Danny, July 28, 2009
Derek, Seagate's *normal* operating temperature is up to 60C
Optical drive installation
written by Danny, July 29, 2009
Hi Fernando, DVD drive you bought UJ-875S is the correct part. If installed properly it should work straight away. I would suggest that you contact people you bought it from (OWC) and discuss possible replacement.
Thank you so much.
written by Fernando alves, July 29, 2009
Hi, Danny,

Thank you for your prompt answer. The Mac community will always be indebted to you. Great web site and perfect answers. I'll be getting a replacement drive. When I get it and have it working, I'll tell you. smilies/smiley.gif
Model number
written by charles, July 31, 2009
Hi Danny,

A great document you have assembled!
I have a few questions though. My iMac is a November 2007 alu 20" model and its model number is A1224. I can't see that model in your list at the top of this page. On the other hand I can't find anything that resembles one of the model numbers you mention there on or in my iMac.
My next question concerns the CPU. Can you tell me, or anyone else, which CPU do I exactly need if I want to upgrade from the original 2.0 to a 2.8 GHz?
Thanks in advance.

written by Danny, July 31, 2009
Hi Charles,

Your system should be with 667 FSB (front side bus), so you can use any Intel Core2Duo MOBILE CPU at 667 Mhz, please chesk out this Intel Mobile CPU table.

written by charles, July 31, 2009
Hi Danny,

Thanks for your quick response. My system info profile says that it has a 800 MHz bus speed and by the way that it's an iMac 7.1.

written by Danny, August 01, 2009
Hi Charles,

Thanks for that info. In such case I believe you have T7300 CPU inside your iMac (800 Mhz, 2.0 Ghz CPU). You can go with Intel C2D T9300 mobile 2.5 Ghz CPU or Intel C2D T9500 mobile 2.6 Ghz CPU in your case.

Another Satisfied Reader!!!
written by Hank, August 03, 2009
Just installed a 1.5TB Barracuda. Instructions were easy to follow. I had a SATA/USB drive adapter (~$20) so was able to SuperDuper the existing drive before I followed these instructions. I CA'ed (Super Glued) the thermometer on the HD.
Upgrade succesful
written by olav, August 03, 2009
Hello Danny,

I have completed the upgrade of my 20' iMac successfully. I decided to go with the latest 2TB WD hard disk even though it was a bit more expensive.

With the help of your instructions and the photo's which I had at hand on my macbook (always nice to have two computers) it was very easy to do.

A few minor details, my display was attached to the main body with screws as well. And I succeeded in disconnecting the connector in the upper right hand corner and then lift the display up from the top. I 'secured' the display by leaning it against some styrofoam and a wooden kitchen spoon which gave me enough room to get to the hard disk.

In the end it was all very easy, I had no parts left (always a good sign) and my iMac was up and running within 45 minutes. I decided to do a clean install and manually import whatever I felt I still needed and get rid of all the stuff I had downloaded and was not using anymore. I have now 1.3 TB available space!!

What is the most impressive thing about the upgrade is the noise or lack of it. My iMac is now dead quiet, a very welcome change after the noise of my old hard drive. The upgrade would have been worth it just for that reason. Many thanks to your manual, much appreciated.

written by Becky S., August 07, 2009
Well, I'm not sure what to do. My iMac won't boot up. Spins and then turns off. Took it to Apple store. They said the hard drive's going bad and it's 275 for a new one. I said no thanks. Bought a Seagate 1.5 and planned on changing it myself. I looked for my Leopard disk and can't find one. THis was a refurb. mid 2007 but I'm sure they sent one. I do have a usb enclosure. Of course, I didn't back up my computer but there's really nothing on there that's not on my MB Pro. Can I take Leopard off the MB Pro somehow? Should I take out the bad drive and try to see if it works in the enclosure. I haven't tried Disk Warrior but they probably did at the Apple store. They tried to get it working while I was there and tried a bunch of stuff. Any thoughts for me?
written by Becky S., August 07, 2009
I found the OS disks. They were in the keyboard box in a little package that said "everything else." Good thing I didn't throw it away! Now, hopefully I won't have problems installing to a new HD since these are packaged with the computer.
Leopard install discs
written by Danny, August 07, 2009
Hi there Becky,

You can always order replacement Leopard discs from Apple - every Mac owner can order replacement discs for the cost of media only and I believe this is $34 (at least that's what I've paid couple months ago when I lost my MB Pro install discs). On the other hand you can always borrow your friend's discs... smilies/smiley.gif

In your case, you should install the new 1.5 TB hard drive and do a clean Leopard install. Then connect your old hard drive to an external enclosure and attempt to recover some data from it. If unsuccessful (and I'm skeptical you'd be able to recover data from it if it is badly damaged as you described it), you can always transfer data from your MB Pro.

Question on Optical Drive protocols
written by Rober, August 08, 2009
I'm going to be replacing an optical drive in an friend's iMac Alu next week, and thanks very much for this procedure. I have a question about replacement drives. My friend's unit is a 2.0 ghz iMac7,1. Is the optical drive in that unit a ATAPI or a SATA? The drives you reference above as replacements seem to be ATAPI. Can a SATA work with the same interface as an ATAPI?

Sorry if this is a dumb question. Dont mean to waste anyone's time.
OSX Won't Install
written by Mark, August 14, 2009
I followed all the recomendations for installing a new HDD. Now OSX won't install on the new drive. i just get a flashing folder with a "?" in it. Any suggestions? [iMac 24" Alum.]
OS X installation
written by Danny, August 14, 2009
Hi there Mark,

If the hard drive is installed and connected properly (power and the data cable), the flashing question mark "?" folder is quite normal as the system is trying to boot an operating system and it is not finding it.

Inserting an OS X install DVD might not start automatically by itself, so what you need to do is restart your machine and hold the OPT key just after the chime sound. You will get a graphical boot menu in which you have to choose the DVD volume (OS X install disc) to start the system from. Once the installer starts, you need to find Disk Utilities in the navigation menu to partition the hard drive. Once the partitioning is done, you can proceed with OS X installation. Once the installation is completed you should be able to boot the system from the hard drive and subsequently run Migration Assistant (from Utilities) to import data from your old hard drive (i.e. connected to an external USB enclosure).

On the other hand, when manually choosing to boot from DVD (holding the OPT key down after the chime on reboot), if it cannot find any hard drive in the disk utilities (you must start Disk Utilities once in the OS X installation menu), it might happen that the system is not finding any hard drive - in such case you have to make sure power and data cable were properly attached during the installation.

Hopefully it is just the manual selection to boot from the OS X install DVD in your case.

written by Mark, August 14, 2009
Thanks for your quick reply Danny. I did as you suggested; after holding down the OPT key on start up all i get [after a minutet or so] is a blank screen with the mouse arrow [that i can move] I know the HDD is getting power i hear it running and it is heating up. I Have also tried the COMMAND - OPTION -P-R boot up as well. No other keyboard boot command works.

written by Mark, August 14, 2009
...also the OS X DVD is in the drive but there is no activity form it.
Re: Question on Optical Drive protocols
written by Danny, August 14, 2009
Hi Robert,

Your iMac 7,1 should be 2007 model and this model is using ATAPI DVDRW superdrive (compatible models UJ-875, UJ-857).

No, you canot mix SATA and ATAPI drives. SATA is a newer technology used in the latest machines.

Re: OSX Won't Install
written by Danny, August 14, 2009
Hi again Mark,

The normal operation after holding the OPT key on reboot is to get a menu depicted exactly as in this article which will allow you to choose DVD to boot from.

You say you can hear your hard drive spinning, but there is no operation from the DVD, and you are also getting a blank screen. First you should try resetting your iMac PRAM as described in this article. Hopefully this should do it.

Also try holding down the primary mouse button during the reboot, this should eject the DVD and prove that DVD is getting power, and you can also verify that disc is not stuck in the drive.

If your DVD is not operational for some reason, you can also try attaching an external hard drive or a flash memory drive of sufficient capacity with OS X installation (you can use Disk Utility on another Mac to copy - restore the content of OS X install DVD onto a hard or flash drive) and try the installation from the external hard or flash drive (you choose it by holding the OPT key down during the reboot).

If none of the above is working, you could verify (with opening your iMac) that everything inside is connected as it should be and that you perhaps didn't miss attaching a cable in there.

Hopefully some of the above will work out for you.

Umbelivable....1Tb, now I can swim inside of this!!
written by Virtualenix, August 14, 2009
just finished installing a new Western Digital WESTERN DIGITAL Caviar Black WD1001FALS 1 Tb 7200rpm 32 Mb buffer drive in my iMac 20" 2007.
So far so good!
Thanks for posting this tutorial it made things much much easier.

The results of XBench:
System Info
Xbench Version1.3
System Version10.5.8 (9L30)
Physical RAM4096 MB
Drive TypeWDC WD1001FALS-00J7B1
CPU Test125.20
GCD Loop234.8112.38 Mops/sec
Floating Point Basic112.492.67 Gflop/sec
vecLib FFT92.723.06 Gflop/sec
Floating Point Library124.7621.72 Mops/sec
Thread Test165.38
Computation170.873.46 Mops/sec, 4 threads
Lock Contention160.236.89 Mlocks/sec, 4 threads
Memory Test146.39
Allocate199.87733.98 Kalloc/sec
Fill124.686062.36 MB/sec
Copy133.562758.57 MB/sec
Copy140.512902.26 MB/sec
Scale140.062893.56 MB/sec
Add154.093282.52 MB/sec
Triad152.583264.00 MB/sec
Quartz Graphics Test159.16
Line144.629.63 Klines/sec [50% alpha]
Rectangle192.0557.34 Krects/sec [50% alpha]
Circle155.8212.70 Kcircles/sec [50% alpha]
Bezier151.323.82 Kbeziers/sec [50% alpha]
Text159.559.98 Kchars/sec
OpenGL Graphics Test152.25
Spinning Squares152.25193.14 frames/sec
User Interface Test259.97
Elements259.971.19 Krefresh/sec
Disk Test94.77
Uncached Write172.30105.79 MB/sec [4K blocks]
Uncached Write170.3596.39 MB/sec [256K blocks]
Uncached Read89.7826.28 MB/sec [4K blocks]
Uncached Read218.97110.05 MB/sec [256K blocks]
Uncached Write25.182.67 MB/sec [4K blocks]
Uncached Write330.25105.73 MB/sec [256K blocks]
Uncached Read111.520.79 MB/sec [4K blocks]
Uncached Read187.4434.78 MB/sec [256K blocks]
written by Marc, August 17, 2009
Just replaced dead internal HDD on 2008 aluminum 3GHz machine. Didn't disconnect the iSight. Glass front came off quite easily - much less stressful than I thought.

Good instructions, thanks.
New 1.5 TB!
written by Ben, August 30, 2009
Just replaced the 320 GB hard drive on my iMac 24" 2.8 GHz. I didn't disconnect the iSight, just flipped the case over while lying flat and didn't disconnect the LCD, my wife held up the display while I worked inside. Put in a new Seagate Barracuda 1.5 TB and everything is running smoothly.

Thank you very much, Great tutorial!
~ iMac Optical, CPU, GPU upgrade guides coming soon! ~
written by Don McHose, September 04, 2009
:- The GPU upgrade would be nice for my imac 7,1 smilies/grin.gif
Mic no longer works on IMAC after HD swap and Snow Leopard upgrade
written by John Lee, September 06, 2009
I recently put in a new hard drive in my 24 IMAC 2008. Installed Snow Leopard and restored files from Time Machine. All worked perfectly although some where i lost functionality of my mic including the ext mic jack. Did I pull a cable inside by accident?
Which 2TB to choose for my 2.4 GHz intel Core 2 Duo iMac
written by Richard, September 10, 2009

Can someone please help in which internal HD to choose?
I don't know which one to choose: Western Digital WD20EADS or Seagate Barracuda LP 2TB (ST32000542AS).

I know that the WD is more inexpensive in it's power consumption and that the Seagate is faster.
But my problem is that I would like to have that translated into more understandable examples which I cannot find on the internet sofar.

So is faster realy faster or is it only a figure which is not noticable when your working on your computer. And the same with the power consumption. I know that sometimes when it is stated that something is cheaper than it's rivals, it's actually a few bucks (euros) a year. And in that case it is perhaps better to go for fast.

I hope someone can and will help me with this issue.

Kind regards,
The Netherlands

And PS: please try not to get TOO technical...
Re: Mic no longer working
written by Danny, September 10, 2009
John, I would assume you pulled a cable or a connector inside, the only way to check it out is to open up the machine again and test out the connections. Good luck!
Comparison in performance between 2 TB drives WD20EADS vs ST32000542AS
written by Danny, September 10, 2009
Hi Richard,

I believe you are actually referring to the above posted comparison between 1.5 WD and Seagate drives. However situation with 2 TB WD and Seagate drives is a bit more different as their specifications are so closely matched making the comparison even more difficult.

Let's start with some technical details first that we'll translate later on to more understandable information (for those inpatient, just skip to the Conclusion section).

Power Consumption comparison 2 TB drives WD20EADS vs ST32000542AS

- Readwrite power consumption: 6W
- Idle power consumption: 3.7W
- Standby: 0.8W

- Readwrite power consumption: 6.8W
- Idle power consumption: 5.5W
- Standby: 0.5W

Seagate uses 0.8W more power while working and 1.8W more power while idle, on the other hand WD uses 0.3W more power when in Standby.

Realistic estimation of the actual power consumption is really difficult to calculate as each user uses his computer (and hard drive) in a different way - do you keep your computer working all the time, do you shut it off at night or at times away, how much do you actually use it, how much data do you transfer with it... Another variable is also an average cost of electricity in your area.

Therefore, for the purpose of this comparison, we can only work out a theoretical model - and in this case let such theoretical value be the maximum (extreme) usage of your hard drive.

Let's assume that hard drive will be operational 24/7/365 (which is absolutely not possible, but an extreme example), that would translate to 8760 hrs per year, meaning that WD would use 8760hrs x 6W = 52560wh = 52.56 Kwh of electricity/year , and Seagate would use 8760hrs x 6.8W = 59568wh = 59.57 Kwh/year. If we assume that average price of residential electricity is $0.12Kwh, that would translate to annual consumption of $6.30 for WD vs $7.14 for Seagate - difference being only $0.84 and for theoretical 24/7/365 full-time read/write operation.

Let's see how the same compares if the drives would be idle 24/7/365. I took the calculations on the side (won't trouble you with numbers here), it turns out that if WD was idle the whole year it would consume $3.89 worth of electricity vs $5.78 worth of electricity translating to difference of only $1.89 - again for theoretical assumptions the drives are idle 24/7/365.

The above realistically translates in a very insignificant financial difference in electricity consumption between the two drives. I trust it is safe to say that electricity consumption shouldn't be a purchasing factor for single/home usage in choosing between the two drives (unless you are a data center and have 1000s of hard drives in use).
Comparison in performance between 2 TB drives WD20EADS vs ST32000542AS
written by Danny, September 10, 2009
Read-write performance comparison 2 TB drives WD20EADS vs ST32000542AS

- Sustained data transfer rate: 100 Mb/s

- Sustained data transfer rate: 95 Mb/s

How much are you going to miss 5 Mb/s really depends on how much you are using your computer and transferring large files. Let's work out a theoretical model of copying a file size of a DVD disc, typically 4.7 Gb. This again is a theoretical model and would mean copying from one hard drive to another, not from an actual DVD drive as optical drives are much slower (even 10 times) than hard drives.

4.7Gb equals to 4812 Mb. That would mean that you would be able to copy DVD movie from one 2TB WD drive to another 2TB WD drive in 49 seconds vs 52 seconds from 2TB Seagate to another 2TB Seagate drive - difference being 3 seconds per movie. Realistically you won't be able to achieve these transfer speeds as you would typically copy from your WD or Seagate drive to another, usually much slower media - and the speeds you would achieve would be of that slower media - hence both drives would most of the time achieve the same performance.

Therefore, although 2TB WD is a just a fraction faster drive than 2 TB Seagate, the actual speed difference you'd be able to notice is virtually non detectable for an average user.

Acoustics comparison 2 TB drives WD20EADS vs ST32000542AS

- Idle Mode = 25 dBA (average)
- Seek Mode 0 = 29 dBA (average)
- Seek Mode 3 = 26 dBA (average)

- Idle Mode 1.9 bels (average) = 19 dBA
- Seek typical 2.0 bels = 20 dBA
Seek max 2.2 bels = 22 dBA

In this comparison Seagate does much better than WD in terms of acoustic performance. The difference in idle mode being 6 dB and in typical operation Seagate is 9 dB quieter than WD. The 9 dB sound compares to "calm breathing" - therefore for some sensitive ears Seagate might be a better choice.

Wikipedia's table on sound pressure levels
- Calm breathing = 10 dB
- Calm room = 20-30 dB
- Normal taking at 1 meter (3 feet) = 40-60 dB
Comparison in performance between 2 TB drives WD20EADS vs ST32000542AS
written by Danny, September 10, 2009
CONCLUSION of comparison between 2TB drives WD20EADS vs ST32000542AS

- Power consumption difference between 2TB Seagate and WD is approximated to only $1 per year in favor of WD
- Data transfer rate difference between 2TB Seagate and WD is virtually non detectable for an average user.
- Acoustic performance difference between 2TB Seagate and WD is compared to difference in "calm breathing" - which might be considerable for noise sensitive users. The acoustic performance goes in favor of Seagate being "calm breathing" quieter drive than WD

Therefore the performance between the latest 2 TB WD and Seagate drive is pretty close. For an average user you won't be able to notice any difference on your electricity bill or in terms of speed. However, in a very quiet room you would be able to notice that Seagate is acoustically quieter drive. Finally, another purchasing decision between the two drives has to be the price too - which you can check clicking at the following links - current price for 2TB Western digital WD20EADS and current price for 2TB Seagate ST32000542AS.

I hope the above analysis answers your question in as simple terms as possible.

Upgrade iMac 20" 2007 model with Seagate 1.5TB Barracuda
written by Walter, September 12, 2009
Just upgraded my iMac 20" model 2007 using your instructions; no problem; great.

Just 1 remark: i was not able to install OSX Tiger on the blanc disc: error message; tried the procedure with the upgrade DVD Leopard by selecting Timemachine - cancel - continue install: worked fine

Question regarding upgrade of iMac 24 to 8GB Ram
written by Eli, September 13, 2009
Can somebody advise whether it would be possible to upgrade a late 2008 3.06GHz, iMac 24 to 8GB Ram (2x4GB).
If Yes, which RAM modules?
Re: Comparison in performance between 2 TB drives WD20EADS vs ST32000542AS
written by Richard, September 14, 2009
Hello Danny,

Here is my last sort of idea / question regarding which drive suits me the best and therefore which one I'll buy.

But first of all I was overwhelmed by your more than detailed reply...WOW, thanks for that. It was really understandable to me and maybe also for lots of other not so experienced people who are reading this.

But having read your reply, it makes me more than ever wonder if speed is not the major issue what makes one decide which HD to build in. Up till now I was thinking to get more storage room and because my iMac is on pretty much all the time, I was also concerned about it's power consumption.

But I saw in your comparison the sustained data transfer rates of the two drives: 100 Mb/s vs 95Mb/s. And earlier I read that the Seagate 7200.11. 1.5 TB has 120 Mb/s.

And with my rookie experience that seems to be a huge difference. And because of the fact that I also want to use Final Cut Studio on it, the Seagate seems to be the best option. And I have read it's also sort of green. But even if it's not, through your comparison I have noticed that the electricity bill is more or less to be neglected.

So my last question before buying the "right disk for the job".
Shall I notice a big difference between my earlier choice and latter? Now knowing that I also want to use FCS and having my iMac on during certainly during day & night?

You don't have to be as detailed as before, for I don't want to burden you to much.

And sorry for hesitating (lol)

Thanks again and keep up the good work.

Kind regards,
An admirer from Holland
1.5 TB vs 2.0 TB
written by Danny, September 14, 2009
Hi Richard,

I wrote the above comparison between 2TB drives for everyone's benefit (this web page has lots of readers).

You are essentially asking now how to compare 1.5TB and 2.0 TB drives and what are the pros and cons between them.

The simple answer is as follows - if the storage space is what you need the most - you should consider having one of 2TB drives, and if speed is more important to you, go with 1.5 Seagate as additional 20Mb/s is a significant performance gain as compared with 2TB drives (100 Mb/s for 2TB drives vs 120Mb/s for 1.5 Seagate).

In my personal setup, I have 1.5TB Seagate inside of my iMac as I prefer the speed and a snappy response, especially when multitasking between a number of applications and copying files in the background back and forth. As far as the storage capacity goes, I use an external 4TB (2 x 2 TB) hard drive enclosure which takes care of storing those huge files.

Reply on 1.5 TB vs 2.0 TB
written by Richard, September 14, 2009
Hi Danny,

Your answer is exactly what I got in mind when reading your first answer. And I have come to the conclusion that 1.5 TB is already a lot of storage. And I don't want to think in retrospect, that I better should have went for a slightly faster machine. For after all, that is something that's noticeable everytime I'm behind my Mac. And that's a lot!!

And extra storage can indeed easily be solved by connecting a external drive. So I'm totally convinced to go for the 1.5 Seagate although in my search till now I read somewhere that a 7400 RPM drive is probably too hot for a iMac or mainly too hot for it's heat sensor. But hearing that you have one build in yourself, makes me convinced that it works well.

Thank you, and in time I will let you know my findings after having it ordered, received (out of the States) and of course build in!!!

Best regards
Great guide - but I'm experiencing a big performance drop using WD Caviar Green 2TB
written by Picard, September 18, 2009
.... after fitting the drive into my 24" iMac (which I had cloned from the original 320 GB drive using Super Duper) it wouldn't boot and log lots of I/O errors. After booting from my Snow Leopard DVD and using Time Machine to restore the last backup to the new drive ... those errors were gone and the system would boot normally. After the whole spotlight re-indexing was done I could notice a steady de-gradation in hd performance. The system feels unresponsive and XBench only shows maximum read rates of about 10-20 MB/s . SMART has been fine all the time ... any clues about that?
Re: performance drop
written by Danny, September 18, 2009
Hi Picard,

It sounds like the cloning might have been the root of your problem from the start -- I would suggest a fresh, clean OS X install.

written by Branko, September 22, 2009
Hi Danny. Thank you very much for this review.
Last night we my friend and I replaced in the iMac 24" alu 320 hard drive with 2 TB Caviar Green, made backup via Time Machine. Everything went OK at best.
The only thing plaguing me for the time machine is 1 TB capacity compared to 2 TB of this
How do I (when this Caviar Green ran 50% of capacity) to work on the Time Machine.
Do you have any advice on how to transfer the entire Time Mackine on other hard disk (2 or 4 TB) ?
Thanks again...
Fan trouble after the upgrade
written by Renato, September 23, 2009
Hi Danny, I made the upgrade with the 1,5 TB Seagate, and after some hours, the cpu fan went to 3500 rpm, just like Derek wrote some months ago. In the Hardware Test, it showed the problem code 4SNS/1/40000000:TLOP-70.187
I know it is sensor related, but as the number of the code is slightly different from the one from Derek, I wonder if you know exactly what sensor is damaged. I didn't manage to find this exact code on Google, maybe you know someone with a Apple Service Manual that could check it out for me...
I would really appreciate any help!
Time Machine
written by Danny, September 23, 2009
Branko, I wouldn't be worried about Time Machine hard drive being smaller in size than the internal hard drive. First of all NOT all files are being backed up to the time machine - (e.g. operating system files, etc.) - files being backed up are user files, user settings and applications - therefore you shouldn't assume that for 2tb of internal hard drive storage you need 2tb external time machine drive. Also, you can manually select (in System Preferences, Time Machine) certain files or folders you don't want your time machine to back up -- I use this for example to prevent the time machine from backing up my movie library - as these files are being huge and on the other hand it is not important for me to back them up. Therefore using a common sense logic and understanding of which large files or folders you don't need backing up, you can setup up this option and save some time machine space if you are really jammed up. Also, time machine automatically backs up the latest version of your user files and if it runs out of the space it deletes the oldest backups. Lastly, it is going to take you a really LONG time to fill up 2tb.

You might check out this official time machine guide (Apple support link).

Re: Fan trouble after the upgrade
written by Danny, September 23, 2009
Renato, I'm sorry to hear this. I've literally had hundreds of people reporting on successful hard drive upgrade following this guide, however cases like yours are very, very rare. Similar to Derek, you must have damaged one of the internal sensors during the upgrade. Unfortunately I don't know which sensor exactly is related to TLOP-70.187 error code (and I also could not find it on Google). I suppose you will have to take your machine to Apple for service. Sorry I couldn't be more helpful. Perhaps someone googling this post with a solution might be able to help out at some point in the future.

Re: Upgrading iMac 2008 to 8GB Ram
written by Danny, September 23, 2009
Eli, iMac 2008 cannot be upgraded to 8 GB RAM, it is designed to accept only 4 GB RAM (starting with iMacs 2009 it is possible to upgrade them to 8 GB RAM). However, it is known (unofficially) in the Mac community that you can upgrade your iMac 2008 to 6 GB max - with one 4 GB 800Mhz module and one 2 GB 800 Mhz module.

Re: Fan trouble after the upgrade
written by Renato, September 23, 2009
Danny, thanks for the quick answer, I will follow your advice and take it to Apple.
As soon as I have an answer from them of what went wrong I will update here.
Congratulations for your page, it was very helpful!
Installed Seagate Barracuda 7200.11 1.5TB
written by Richard, September 24, 2009
Hi Danny,

Just to let you know, I have just installed the 1.5TB Seagate drive successfully. Thanks to your help you just saved me about € 240,-.

So thanks again and for anyone who's still hesitating: Just go for it!!! If you do the procedure step by step and don't rush things, it is very easy!!!

But Danny if you think that you just got rid of me (LOL) you're mistaken, because I have another question for you about upgrading my RAM memory. Normally this subject wouldn't be question-worthy in my opinion because upgrading ones RAM memory is dead-easy. But in a recent comment of yours (September 23, 2009) I saw you mention that an iMac 2008 can be upgraded (unofficially) to 6Gb.

So you know perhaps why this is? Because I seems to me that if one slot can have 4GB why not the other also and come to a total of 8GB? And can it only be done with the particular one to which you link?

Thanks again,
6GB RAM for iMacs 2007 and 2008
written by Danny, September 24, 2009
Hi Richard, congratulations on your hard drive upgrade!

In terms of 6GB RAM, both iMac 2007 and iMac 2008 can be upgraded to 6GB due to the fact that they use the same chipset (Santa Rosa) used in Macs officially certified for 8GB.

This wasn't known at the time these machines came out as there were no 4GB memory sticks available at the time. Sure, you can install 2 x 4GB RAM in both slots, it will show up as 8GB, but it will NOT work, the system will freeze and crash - therefore 8GB in iMac 2007 and 2008 is highly UNSTABLE (this is just the way it is, the motherboard was not engineered with 8GB in mind for these models).

6GB is the unofficial maximum that can work well and be stable on both iMac 2007 and 2008 (including all unibody laptops certified originally for 4GB) - confirmed by actual users in several Mac community forums (if you google it there are lots of pages on it).

As far as which memory to install, it is interesting to note that you will often hear selling pitches such as "Apple memory" or "OWC memory for Macs" - the best kept secret in the Mac world is that these are only selling strategies, as you can use memory from ANY manufacturer that complies with your computer's technical specifications (even "PC branded" memory).

For example, Apple doesn't make its own memory - sometimes in Macs you will see Hynix or other memory modules installed by Apple. OWC memory is nothing but a label on a memory stick with Samsung (or other) chips (and there are only a few memory chip manufacturers in the world). Then when you compare the price tag between "Apple certified" memory and memory sold for PC laptops with the exact same technical specifications (btw. "PC branded" memory works great in Macs too), the price difference is quite radical! They use the same memory chips, so what is the extra cost for? - it is the tax on perception of a brand value and a quality.

Personally, I would use parameters such are warranty (many quality memory manufacturers offer lifetime warranties) and return policies in choosing memory for my Mac (regardless if the memory is Mac or PC laptop branded - chip wise its all the same).

Having said the above, you can upgrade iMac 2007 to 6GB RAM with one "2GB 667Mhz unbuffered so-dimm" and one "4GB 667Mhz unbuffered so-dimm" memory stick from any manufacturer (even if it is sold as a PC memory) complying to PC2-5300 specification.

Similarly, iMac 2008 can be upgraded to 6GB RAM with one "2GB 800Mhz unbuffered so-dimm" and one "4GB 800Mhz unbuffered so-dimm" memory module from any manufacturer (PC branded memory too) complying to PC2-6400 specification.

I have updated the above article memory upgrade section to reflect this accordingly. You can also reference iMac RAM memory upgrade table to determine RAM upgrade options in your case.

Re: Upgrading iMac 2008 to 8GB Ram
written by Eli, September 25, 2009

Thanks for the answer.
I have the Leopard Snow installed which should presumably support 8GB.
Now, if one 4GB module can be installed, wouldn’t it be possible to install two of them?

Regarding the upgrade to 1.5 TB drive, I have done it and it went smoothly but with a small modification:

Rather than disconnecting the 2 display connectors at the bottom of the of the display, which I found difficult to locate in my iMac 24, I brought the iMac back to vertical position.
I then pulled the upper part of the display away from the mother board, while holding its lower part tight, thus creating an opening (like a V) in which I could push my hand and release the 3rd display connector from the display itself (hidden by a black tape that has to be removed first) rather then from the small blue board. No unscrewing was required.

While standing, I then leaned the display on my belly so it stays stable and with two hands comfortably released and replaced the drive as described in your instructions.
Once replaced, I reconnected the connector and pushed back the display to its position.
Thanks for the great instructions you drafted in your blog.
Other updates
written by David, September 25, 2009
Danny, thank you for your effort to help the iMac community. I am planning to upgrade my HDD on xmass.
However I am looking forward for your other articles: upgrading CPU, GPU, Opt. drive... Have you any idea when they will be available (probably I would go for a complete upgrade at once smilies/smiley.gif

Thank you!!

Reply to Eli and David
written by Danny, September 25, 2009
Hi Eli, thank you for sharing your experience with us - your approach to iMac hard drive upgrade standing up is certainly not for everyone or faint-hearted smilies/smiley.gif In terms of 8GB on iMac 2007 and 2008 - I don't think Snow Leopard will make any difference - it won't work - you can upgrade these models to max 6GB and that's 2GB above original manufacturer's specification. Unless you are doing some really heavy pro stuff it is very, very hard to use up 8GB of RAM at any single point - even if you run two virtual machines (e.g. Windows and a Linux) in the background.

David - I haven't got the time to post up the GPU and other upgrades and I didn't think of it as a priority as there is lack of genuine Apple parts (iMac MXM GPU cards) on the market and they are so highly priced making the project financially nonviable in my opinion. While hard drive or RAM DIY upgrades make lots of sense (financially), not all upgrades are cost effective. I was also thinking of an alternative cost-effective solution - taking a non-Apple graphics card (e.g. high end ATI or NVidia) and trying to run it on an iMac - but such solution would require appropriate graphics kexts developed (in PC terms "video card drivers") and installed on the system - due to which there could be problems booting the machine on clean reinstall or loosing the capability once you upgrade the OS - that is unless a third party graphics card can be flashed and reprogrammed to bare a hardware ID of a genuine Apple graphics card... you can see where I'm getting with this - lots of time in development would be required in order to make the graphics upgrade financially viable at this time. Not to discourage you, but at this point you'd probably be better off selling your existing machine and paying the difference for a brand new model rather than paying for an iMac GPU upgrade.

In terms of the DVD upgrade - you already have one of the "fastest" DVD-RW models available - the optical drive guide could really serve only as a repair guide. Perhaps a blue-ray upgrade would be worth it - I'd need to look into it.

Finally, if some of you guys have free time on your hands and want to help out in any of these projects - this is purely voluntary to have fun and also to give something back to the community - give me a shout.


written by Bjarki, October 01, 2009
I replaced my hdd because it had failed.Everything went fine until i tried to turn it on again after having replaced the old drive. It just restarts continuously right after the sound comes sometimes before that. the first time i turned it on the gray screen appeared but only that time. Does anyone know what the hell is going on?
Missed important step!!
written by Jurgman, October 04, 2009

If you forget to transfer the EMI thingie than your hard drive will humm like crazy.
I did and i had to reopen the thing. iMac is allmost quiet now.
Nice upgrade guide
written by DV, October 08, 2009
These instructions were helpful. I just upgraded my 24" 2007 iMac from 320GB to 2Tb (WD RE4 GP (FYPS)) drive yesterday. Quiet and seems to work well! Thanks again
Anyone tried to upgrade to a SSD drive (solid state drive) yet...?
written by Larry , October 08, 2009
Thinking of putting a SSD drive into my 2008 iMac to replace the 500GB hard drive
but the cost is $300.00 Plus for only 120 GB. Bootup speed and App speed would
be the motivating factor for doing this. Only using 80 GB now so 120 limit wouldn't
be too bad and I use it mostly for iMovie, iWeb, and GarageBand. Editing HD vidoes
in iMovie would be incredibly smooth and fast. Anyone tried this?

Blue/Gray and Pink/Gray connectors behind the LCD . . .
written by Mahesh, October 11, 2009
Great Article!!! Thanks a lot.

I just ordered a 1TB Western Digital Caviar GreenPower. For a rehearsal, I just finished dis-assembling and re-assembling the imac 2007 based on your instructions! They were very useful and clearly laid out.

I think I made a mistake.

On the back of the LCD panel, there are two connectors, Blue/Gray and Pink/Gray. Before realizing to mark them, I disconnected both these. After that, I did not have a choice but to make a "educated" guess on connecting them back. I have assembled the imac and booted. Every things seems to be working fine. I tested the camera, DVD player and they seem to be working fine!

I do not know, if I REALLY got lucky! What happens if the polarities for these connectors are reversed or incorrectly connected?

Any way to identify and connect them properly?

Re: Blue/Gray and Pink/Gray connectors behind the LCD . . .
written by Danny, October 11, 2009

If you reverse polarities of connectors, things can go really bad - especially if this is a power lead... having said that Apple usually designs connectors to be of different shapes sizes, and also each connector has a tab preventing it to be wrongly inserted where it's not supposed to go. Just observe connector sizes and tabs carefully, and don't force anything in -- if it's not easy to plug in and if you need to force it in - it usually means it's not meant to go there.

Good luck upgrading!

iMac20" 7.1 6-cables, left 4 connected
written by tadd, October 16, 2009
I discovered that my display had 6 separate cables, two which were connected to the motherboard below the display, as pictured in your excellent article, and 4 which were connected to the right hand side of the monitor and which were all small connectors. Having unconnected only the first two cables, I was able to lay the iMac on its back and stand the monitor up with the right edge sitting on the table and held from falling by a 3rd and 4th hand, leaving the latter 4 connectors still connected. Now I was able to quickly swap the HD out, forgetting the ESD item, oops. I don't know if I'd have done it just for an upgrade knowing how difficult it was (over 50 and eyes are getting worse) but your instructions pulled me through.
Thanks. May I suggest adding a better close-up of the two connectors below the display. The cable to the connector near the fan went under the fan and was kind of stuck there. Since the wire went from a net-shrouded cable to separate wires while it was UNDER the fan I couldn't tell what connector I was unplugging. After I started removing the display I was able to wiggle the wire loose enough to identify which connector it was.
written by Dan, October 21, 2009
A very, very handy article - thanks Danny smilies/smiley.gif
written by Cricky, November 03, 2009
Nice guide! Just bought myself a second hand iMac and this will definitely come in handy when i upgrade it! Thanks smilies/grin.gif
I replaced dead drive with 1 Terabyte
written by Andy, November 05, 2009
thanks for this guide. It really came in handy. I also taped the screws to paper so I knew where they went. On the little tiny screws on the connector at the bottom of the board I put those back in with the computer sitting up that way if I dropped them they would not fall into the computer but onto the work surface. I only unplugged the bottom wires from the screen not the power. I had my wife hold the screen up while I pulled out the old drive and put the new one in.
Hitachi Deskstar
written by Pascal, November 07, 2009
Thank you very much for your very clear and helpful website. I wouldn't and couldn't have done the upgrade of my iMac without it.
I have replaced the original WD3200AAJS (320GB) drive of my late 2007 iMac with a Hitachi Deskstar 7K2000, which is a 7200rpm, 32MB cache 2TB drive.
In terms of speed the drive performs quit well, it is noticeably faster than the Western Digital drive it replaced. The drive does become a little more more: 51C/124F than the original drive. The hard drive fan turns at 1200 rpm, which I believe is no more than originally.
A little disappointing though is the seek noises the disk makes! On idle, the drive cannot be heard, but when in use, the seek noises are clearly audible. The original drive was near quiet !
This drive is retailed in the Netherlands at this moment for approx. €150,- which at the current exchange rate is approx. $225 US.
Overall i think the replacement was ok. The seek noises of the drive, I still need to get used to. (is still less noise compared to what my MyBook Studio drives produce, that sit next to my iMac). But due to the fact that I now have 2 TB of storage available, one of those drives can be put to use elsewhere.

The replacement itself. I used one large suction cup, that is normally used to keep my TomTom navigation system to the windscreen. Just put that in the centre of the screen and you can lift the glass easily from the front panel. I didn't remove the display. I only disconnected the two leads at the rear of the screen in the top right corner. When the screws that retain the lcd panel have been removed, the panel can easily be lifted from the top and kept in that position, by putting a stick underneath it (like when you open the bonnet of a car). Also the iSight connectors do not have to be removed, when you "flip" the front panel on the desk.
Thank you... worked great!
written by Michael Poczynek, November 09, 2009
Thanks very much for taking the time to put this on the Net. I am a computer tech, and I was a little nervous at first, wondering if I would end up with nothing but a large box of broken iMac compenents. Regardless, I followed your instructions, and it was very easy. Much easier to do then you would believe. In my case the hard disk was dead, so I needed to replace it. I replaced it with a Seagate 750G. Worked flawlessly. I found the suction cups in the Christmas section of a local store. The only thing I would add is; put the suction on all 4 corners of the screen, as there are magnets all around the plexiglass screen. Your puctures almost make it look like you are going to hinge or fold the screen down at an angle, which is what I did. In turn I bent one of the alignment pins at the bottom. Yes, there are pins all around the screen to line it up. Looking back the only thing I would have done differently is; use two people to remove the screen and lift evenly from the main chasis. Everything was smooth as can be. Thanks!
IMac Aluminium, lightning edition.
written by Iain Sinclair, November 14, 2009
Thanks for the upgrade guide. It made a potentially disastrous job, into an easy one.
For all the UK upgraders, go to B&Q and ask for glass suction cup lifters (£8 ea), for removing the glass front.
I got a friend to hold the LCD panel up, whilst I changed the hard drive; negating the need to disconnect it.
I got the recommended Seagate 1.5TB hard disk, and 4GB of memory, which has resulted in a lightning fast machine......I am delighted!!
Ram and Memory upgrade completed
written by Chuck Brewer, November 23, 2009
I have a 2007 Imac and this worked without a hitch. Only difference was the LCD was held on by eight T8 screws (four on each side, all identical) and there were two sets of connectors under the monitor on the right-hand side.

Now, I'm boosted to 6 Gig Ram and 1.5 TB drive.

My Imac has a 2.4 Ghz Intel Core 2 Duo and ATI Radeon HD 2600 Pro with 256 MB. Did a cursory search and it seems my CPU upgrade options are pretty limited (2.6?). Would like to know if there are graphic or further CPU upgrades worth doing.

Thanks for the great instructions!
written by Jeff, November 30, 2009
Just upgraded my 320 stock HD to the 1.5TB drive from Seagate. The drive itself is a bit loud, but worth it for having the space. Your guide was amazing. Saved me time and money. Thanks so much. I owe you one.

Confirmation/Help Needed
written by Lisa, December 02, 2009
I have a 20" iMac, Early 2006 model. My hard drive crashed. Obviously out of
warranty. Took my iMac apart to retrieve the hard drive, placed it in an
enclosure to see if I could get a read off the drive, but nothing.

Since I've gone this far, I want to go ahead and replace the drive myself. I
want to upgrade with a Seagate Barracuda 7200.11 1.5 TB SATA 32 MB Cache
Bulk/OEM Hard Drive ST31500341AS
Would you know if this is compatible? I see you have made reference to 2007 but not 2006.
Much thanks.
Additional Comment
written by Lisa, December 02, 2009
I am replacing a WD2500JS / 250GB SATA / WD Caviar SE
Great Guide
written by John, December 02, 2009
I have just completed my hard drive changeout, following the comprehensive guidelines provided. They worked great. I have a fall 2007 iMac and had the same experience as Chuck / Nov 23, 2009. I had the 8 screws (4 each side) to hold the LCD in place, plus the 2nd set of connectors. Since I had a large enough work space, I was able to flip (rotate gently!) the frame over and did not disconnect the camera.

I was extremely surprised at the lightness of the glass panel. I had purchased 2 industrial suction cups at a local hardware supply. I most likely could have used some kitchen / bathroom suction cups as Danny used. They most likely are the most economical solution as you just need some stead pressure to break the first magnet hold and then you could just lift the panel. It reinstalled very easy.

I had a little trouble getting the aluminum frame off first. It seemed to hang on the bottom part, but was able to gently work it around and get it lifted. I bought a Seagate 1.5 TB raptor drive. I had already upgraded from 2 to 4 GB RAM before I read the posting on the 6 GB option. Previous research indicated a 4 GB max. the 2x2GB SIMMS seem to be the most economical upgrade at the time. My original HD totally crashed (WD 500GB). Not sure why. I restored the setup from Time Machine and the iMac really zips along with the Seagate.

Only part I didn't install was some little cushion / shock absorber. I didn't want to take the computer back apart again just for that and have not noticed any unusual vibration (yet).

Again - great guideline.
Which Drive??
written by paul, December 03, 2009
Ok my 320gb HDD in my 2008 Imac is almost full so i need to upgrade to a new HDD that is 1tb or bigger. I have been doing alot of reading and am still lost in my decision. Im not worried about the price but i want a drive that is faster then the standard WD drive but also keeps cool enough for the tight Imac enclosure. At first i was set on a WD black but i have read about people having heat and noise issues with them. I also thought about the Seagate 1.5tb but all ive read about is bad reviews on these drives failing quite quickly with bad clicking noises and firmware problems. Then i looked at the new Samsung spinpoint f1 1tb which seems to be a great drive all round, very quiet and very fast. Any input on these drives as ive usually stuck with WD and Seagate?
written by Al, December 04, 2009
We purchased an i5 and i7 iMac installed Win 7 and Everquest 2 and (crossing fingers) experienced none of the problems in this article. The 3 year warranty now sounds like a wise choice considering the 1 year failure rate of some hard drives. Who can have a device as cool as these and not wonder how they were able to get it all packed into the monitor. Thank you for the education, we feel more comfortable knowing how it all fits, and enjoyed reading all the inputs and your responses.

Al Tucker

P.S. We have discovered that using an external usb audio amp is a way to feed the iMac audio to our ventrilo computer for gaming using Win 7 on boot camp, hope this helps in some small way.
written by maddogmark, December 06, 2009
I have a late 2009 imac is it possible to upgrade the cpu to a quad chip
written by Dingyu Xue, December 11, 2009
Thanks for the excellent illustration.
I bought a new iMac 950 yesterday and just worried about small Harddisk of 500GB. I browsed the web and found your post. I managed to changed the disk to a 1.5TB one. Now I am putting on my comments:
1) For the latest 950 model, we do not have to unscrew the memory part and the two next to the iSight camera
2) I got only one suction disk of diameter of around 10cm. I put it to one corner, pulled gentally, then put fingers below it, then put the suction disk to the other corner. In this way I got off the protection glass
3) I was worrying about the bluetooth keyboard and mouse. However when I put the install disk in, they are recognized easily, without any problem
4) The HD is not as quiet as it was, it seems
Thanks a lot
Can't install OS
written by Robbie, December 12, 2009
I followed directions and then went to boot from a OS X Tiger disk and a folder with a question mark came up. I tried holding down both "C" and "option" but to no avail. IT originally had Leopard on it, but I don't see how that would matter since I replaced the hard drive. I bought the Mac Box Set to upgrade my Tiger disk to snow leopard since I do not have the original leopard dvd. Any ideas?
The noise and heat increases
written by Dingyu Xue, December 12, 2009
I got my Mac 950 hard disk upgraded to 1.5T Seagate and it seems that the machine is very hot, also very noisy. I am not sure what had happened. Any one has a similar case?
written by peter, December 15, 2009
Im looking to put 2 2.5'' hdds into my 2007 iMac using the patriot convoy XL and using the JBOD configuration because i will be using either a 32gig or 64gig ssd as a bot up drive and to put some programs that I use regularly on it and then a 500gig seagate momentus for storage, but some places that ive gone to for research on the matter saying that this configuration will not work because for 2 drives to work on one sata port you need to have "port multiplying" I was wondering if anyone can confirm or deny this because I was almost set on buying the drives and the enclosure until I herd about this "port multiplier" issue.
Hardware RAID in your iMac
written by Danny, December 15, 2009
Hi Peter,

I was actually discussing this speed kick with installation of two 2.5 inch drives in a RAID configuration in an iMac with a friend of mine a year ago, however at that time the prices of hardware were still too high to make it worth it. However a year later this actually might be affordable now.

The short answer to your question is - yes, it will work.

However, I'm not sure that JBOD configuration - although with an SSD drive will be significantly faster than with a single "classical" hard drive, however I bet that using 2pcs x 2.5 inch 500Gb Seagate Momentus hard drives in a true RAID configuration will give your iMac an amazing speed kick.

Now the long explanation for everyone's benefit:

iMac does provide only one SATA port for a single hard drive, however this enclosure has an internal RAID controller providing two SATA connections internally for two hard drives inside the enclosure.

Utilizing Patriot Convoy XL 2-Bay SSD SATA External RAID Enclosure will allow you to use two 2.5 inch hard drives (e.g. 500Gb Seagate Momentus 2.5in) in a RAID or JBOD configuration. The enclosure has a built in internal RAID controller and it utilizes only one external SATA port. In other words, this 3.5 inch enclosure has the same SATA power and data connectors as on a single 3.5" hard drive used in iMacs, however its internal electronics is providing two ports allowing connection of two smaller 2.5 inch drives in a RAID configuration (data being written to two drives in parallel, theoretically almost doubling speed performance).

Please let us know how did this work out for you and some benchmarks - speed results?

Good luck smilies/smiley.gif

JBOD in your imac
written by peter, December 15, 2009
sorry if this is redundant, but just to make this 100% clear.

the 1ssd and 1hdd in jbod will not work in the iMac using the patriot convoy xl?

if that doesnt work is there any way I can get 2 drives (preferably one ssd and one hdd) to work and show up as 2 separate drives?job
written by Danny, December 15, 2009
I would be able to provide you with a better answer if you should explain a purpose of your proposed modification. I have assumed you want to have a significant data throughput performance increase - as such my answers are tailored in that direction.

Answering your question:

- 1ssd and 1hdd in jbod - Yes, will work in iMac using the patriot convoy xl
- no, you will not be able to see them as two separate drives as by definition jbod puts the capacity of two drives together and you see it all as one big drive (hence the question of the purpose of the proposed modification?).
- I don't think it is possible to see both drives separately in any way, at least not installing it internally - that is unless you want to give up your DVDRW drive and use its SATA connection for the second drive (will work only on the latest i7 iMacs as their superdrives use SATA connectors, unlike the previous PATA interfaces - e.g. similar to installing two drives in the latest Mac Minis by giving up the DVDRW drive).

Usefulness of the RAID setup:

- In my opinion, the usefulness of this setup is to gain a dramatic speed performance by hooking up two drives of the same capacity and configuring a true RAID with this enclosure within the iMac.

purpopse of modification
written by peter, December 15, 2009
my soul purpose was to just have the performace of an ssd and also have the storage of a standard hdd. i mean thats honestly what it comes down to. i would rather have 2 256gig ssd's in raid 0 to be honest but due to the insane pricing that for me is not an option (and any space less than that is not enough for me) so i went for a compromise which has 1 ssd as a standard boot drive and some programs, and then a standard 2.5inch 500gig hdd for storage.

again the soul purpose was to get the performance of an ssd and at the same time get some sort of size upgrade aswell
The rplaced HDD are with huge noise, changed back
written by Dingyu, December 15, 2009
Thanks Danny for the detailed instruction and I did changed with a new 1.5TB Seagate one, as I reported earlier in the post. I have experiencing with fan noise problems, and the case is similar to the post of Derek's. When I changed the original 500GB back, everything is fine. It is quite strange and I swapped them over several times, the same results happened.
Another strange things is that when I installed the iStat Pro on both the disks, there is no display about the temperature and fan speed. It seems that the sensors are not working. The program works well on my MacBook Pro and Makbook 13inch, all of the three machins are working with Snow leopard. The new iMac comes with Max OSX 10.6.1, and the notebooks are with the first release of 10.6. Is it the reason for the bad display of information?
Thanks a lot for the help
written by Danny, December 15, 2009
Hi Peter,

There are three things you can look into in order to take an advantage of SSD drive performance:

1) you can install an SSD internally and have an external fw800 hard drive for the storage

2) alternative is, as you said, to use 2 SSD's in RAID 0 configuration using the Patriot Convoy XL 2-Bay enclosure - being the best and the fastest solution you can have internally to give your iMac a kick in speed.

I also believe that by installing two 500gb Seagate Momentus drives with this enclosure can provide performance increase, for much less money than purchasing two ssds (still being expensive compared to classical magnetic hard drives) - this perhaps would be the most cost effective solution.

In order to compare this, if you use Seagate 1.5TB 3.5in internal hard drive in your iMac (let's say a standard single drive installation), you can get max 125mbps sustained data rate (I'm reading this off the spec sheet). The Seagate Momentus 500gb 2.5in hard drive has 76mbs sustained data rate (again from the spec sheet), therefore if you use two in the RAID 0 mode you will get the theoretical maximum of 152 mps.

In terms of SSD's, let's look at the Patriot SSD hard drives, SSD v2 having 100mbps write and 175mbps read performance, and SSD v3 having 160mps write and 240mbps read performance. Theoretically you can double this in RAID 0 by using the enclosure in question, therefore with SSD v2 get 200mps write and 300mps read performance (not 350mbps as the SATA interface is limited to 300mps), and with SSD v3 get both read and write at 300mps (hence a full utilization of the SATA interface capacity).

3) however, the way you envisioned it - booting of an SSD drive and installing a second drive internally for storage (and seeing them as separate drives) cannot quite work as there are no two SATA ports inside. Using the Patriot enclosure in JBOD mode will not provide you with this functionality.

JBOD stands for "Just a Bunch Of Disks". It's where you use multiple physical hard drives to create one large logical drive. It's not really RAID, but is similar to RAID 0 except the drives are spanned instead of stripped, meaning files fill up the first drive completely, then the second - drives get filled up as each runs out - hence you will not have any performance increase with JBOD. With JBOD you can use hard drives of different sizes and for RAID 0 your two hard drives must be of the same size (capacity). You would need to go to RAID 0 configuration to get the performance increase (hence either using two SSDs or to Seagate Momentus drives of the same capacity).

Perhaps there is a solution on the market that provides port replication of a single to two SATA ports which you would need to research.

Hope the above helps.

Hard drive installation in the latest iMacs i5 and i7
written by Danny, December 15, 2009
Hi Dingyu,

It seems from the earlier post that you have installed a larger hard drive in i5 / i7 iMac (the 21.5 or 27 inch iMac) and that you are having fan speed problems.

While in Derek's case he damaged a temperature sensor in an earlier generation iMac, the problem with the latest i5 / i7 iMacs is that Apple has started using the internal hard drive sensors for temperature monitoring - thefore limiting the types of drives that can be installed in the machine! Sorry to say this but Seagate hard drives are now no longer compatible with iMac i5 / i7. You have also experienced this by moving the old hard drive back in and getting the fans quiet. Apple uses Western Digital hard drives, therefore in order to upgrade the latest i5 / i7 iMac to a larger hard drive, the instructions found here can be used, however you can only use Western Digital hard drives in order to make this work - as Apple is using internal temperature sensors in the hard drive in order to determine the cooling fan speed. This all has to do with the software, perhaps sometimes in the future Apple will allow Seagate hard drives in iMac, however for the time being iMac i5 / i7 users are out of luck and will need to upgrade with Western Digital hard drives only.

2x 500gig RAID 0
written by peter, December 16, 2009
wow danny, that was one very comprehensive answer and I really appreciate the time you took into telling me all that I needed to know.

after reading your reply and doing a lot of thinking i have come to the realization that you are correct with the bang for your buck in the 2x500gig drives in raid 0 in both speed increace aswell as a size increace for me.

but I do have another question too. Im running snow leopard on my system and i have 3 gigs of ram and was wondering if its worth upgrading to the full 6gigs or is 4gigs enough
Decisions, decisions
written by Danny, December 16, 2009
Hi Peter,

You're welcome. The post was also for everyone's benefit.

If you should upgrade the RAM or not depends really on what do you use your iMac for. The same goes in terms of the decision of having an internal RAID 0 installed - what do you need all of that speed for? If you are doing lots of video editing, I can understand the need, but for an average user this might be an overkill.

Everyone's computer usage application is different, that is why you need to measure what you do with your machine in order to determine if you need more RAM, a faster hard drive, etc. What I would recommend to do is to install a really great utility called iStats Menus that will allow you to measure your RAM memory utilization, hard drive performance (mpbs for read and write) and a bunch of other things (CPU utilization, network throughput, temperature sensors, etc)... Therefore by using this utility you will be able to make the conclusion if you need more RAM, faster hard drive (e.g. RAID 0), etc.

Good luck,

written by Dingyu, December 16, 2009
Thanks Danny for your explanation on i5/i7 disks. I will have a try on a Western Digital harddisk tomorrow. That is indeed very strange, since the 500GB one equipped with the computer is a Seagate one.
reasons for upgrade
written by peter, December 17, 2009
I was thinking about upgrading the hard drive because I needed more space and knew the benefits of upgrading to a faster hard drive, but also wanted to make the mac as "upgrade proof" as possible by upgrading to an ssd.(but you have made it clear why to go for the 2x 500gig raid 0 configuration)

as for the ram. I used that iStat program and saw that my hdd and ram use was very high (while running iMovie and iDvd as well as Photoshop)
Re: Help request
written by Danny, December 23, 2009

It's really hard to tell what might be wrong without some concrete diagnostic information. Does the drive spin up? You should be able to hear it powering up. When you boot off the OS X installation DVD and go into Disk Utility (from the main menu), does the drive show up? I would assume that the drive is connected properly inside (two connectors - power and data). If nothing from the above works, perhaps it's a dead drive and you would need to verify that (e.g. if you have an external enclosure or a PC to try it with)...

***Success 12/23/09***
written by Patrick, December 24, 2009
To Danny & all contributors,

Again Thank you for this great thread!!! After buying a new WD-Black 1TB HDD my iMac still would not recognize it, even though it is getting power and all that. So I took my External HDD case apart and started to plug in the HDD's to see if any of them are read-able through my MBP... Funny thing is my original Internal HDD would be detected but not the new HDD replacement. So I went back to Best buy and got a Seagate Baracuda 1TB HDD and surprise surprise!!! Its working! and is more silent than the WD-Black 1TB and cheaper as well by 20.00... So all in all instead of bringing my iMac back to Apple and costing me 3 figures I ended up spending a total of only 90.00 for the HDD Torx set Suction cups. Amazing.

One thing I will always remember from now on though is to ALWAYS run Time Machine!!! Cause by negating to do so I lost all my audio, pictures, movies, and some documents that aren't really critical but I was keeping for record.

Anyhow, my case is closed! I now have a Seagate 1TB baracuda 32mb cache 7200rpm drive in my 24"-AL 3.06GHz w/ 6GB 800mhz RAM. All thanks to each and everyone of you in this board and Special Thanks to Danny for all your input.

I am looking forward for your future GPU & CPU upgrade guide So I can beef up this 3.06 and perhaps upgrade my GeForce 8800 GT to something more meaty in the future.


Extremely Thankful Reader
Raynham, MA
showing (?) mark on startup imac
written by kashif , December 26, 2009
i close my system last night, open today morning but it showing folder icon with question mark, what is this plz help me
written by peter, December 26, 2009
i have been thinking a lot about your comment before about not needing the speed of the raid 0 array (2x 500gig labtop drives in a convoy xl enclosure), but honestly it costs the same as getting one of those new 2tb 7200 rpm 64mb drives and im pretty torn on which to get because it seems like the raid 0 would be faster but the 64mb buffer is making me think other wise

im just wondering what you guys are thinkin and what you would get if you were in this situation
2TB with 64mb cache
written by Danny, December 26, 2009
Hi Peter, I would personally go rather with the latest WD 2TB with 64mb cache (model WD20EARS) rather than with 500GB Seagate Momentus in Raid 0 - I've seen the specs of the new drive, the performance is matching the discussed Raid configuration.


~~~ Happy Holidays everyone ~~~
Thank you
written by cswadner, December 26, 2009
Worked like a charm! I used the Seagate 1.5TB Drive and everything works perfectly. Currently in the process of migrating my data over to the new drive and I am set to go! Awesome work!
? icon
written by Danny, December 26, 2009
Kashif, the "?" icon indicates that the system cannot find your OS or the hard drive. I would assume that your system worked fine the night before you've got the ? icon at the startup. Insert the OS X install DVD. If you hold the option key after the startup chime sound, do you see the hard drive icon? If not, the hard drive is most likely dead. If yes, select to boot from the OS X DVD and when you get to the first prompt, select Disk Utility from the main menu. Does the hard drive show up in there? Try running the disk repair, and try rebooting. Perhaps this should fix the file system if it got corrupted. With the above steps you should be able to figure out if there is a data corruption on your hard drive (steps to fix - repair hard drive from the Disk Utility, or even reinstall OS X if that doesn't work), or if the hard drive does not show up at all, that would mean it crashed and you would need to replace it.

Good luck,


~~~ Happy Holidays everyone ~~~
Just Installed 1TB Seagate -- Very Noisy! Did I make mistake?
written by Andrew Clute, January 01, 2010
Just upgraded a 2.4Ghz 24" iMac from the WD 320GB to the Seagate 1TB (ST310005N1A1AS), and OMG, is it loud!

I can hear every seek on it.

Did I do something wrong on the install, or is this just a loud drive? I would much rather find a different drive that is quieter than live with this. Any suggestions?

Would the Seagate 1.5TB be better (ST315005N1A1ASR), or the Western Digital 1TB (WD10000CSRTL)

Thanks in advance!
Re: Very Noisy!
written by Danny, January 01, 2010
Hi Andrew,

We've had a case like this somewhere above in the comments - it is either the drive itself in which case you have to look into recommended quieter drives (either WD Green or Seagate 1.5 or 2.0TB - I wouldn't have information for lower capacity drives such is yours), or there has been an installation issue with the hard drive mounts - if you believe this is the case you need to go back in and check that the metal pins are properly in place on the hard drive and inserted into the rubber mounts - essentially these are acting as shocksound absorbers.


~~~ Happy New Year 2010 to everyone ~~~
written by mat, January 01, 2010
My 1TB time capsule just died after 18 months. As far as I can tell from web searches it is a power problem and the hard disk is still ok. Is the hard disk from the time capsule interchangeable with my 2007 20" imac. I am thinking that if the disk is still good I could give my imac an upgrade. If it is possible would you consider the disk to be good enough or would i be better using the disk externally and getting a new disk for the imac?

Use the hdd from Time Capsule
written by Danny, January 01, 2010
Mat, if your hard drive from Time Capsule works, you can install it in your iMac 2007 (late) aluminum. The hard drive used in Time Capsule has SATA interface being used in all aluminum iMacs (it is not compatible with older iMac white models). If it is only 1.5 years old, it should still be a good hard drive as the original manufacturer warranties are anywhere from 3-5 years - depending on a brand. You can test if the hard drive works using an external enclosure. All the best, Danny
Installing w/o DVD drive
written by alex, January 05, 2010
Hey guys, I will soon be getting a new imac 27" with i5 processor! So, I currently have 2 SSD's here with me already (30gb each), that I plan on putting in raid 0 with the patriot enclosure. I am planning to have these SSDs take the place of the DVD player on the imac. Although, how will I install the OS on it w/o being able to put a CD in it? Would it be possible to bring the original hard drive onto my PC, as a 'slave' and the SSD's as well and simply copy the original hard drive to my SSD setup? I would think so, but there can always be complications and maybe some registration issues with CD-keys ect ect...

Input would be great!

Thanks in advance.

Installing w/o DVD drive
written by Danny, January 05, 2010
Hi Alex,

That should be possible if you want to give up the DVD drive, it would be an interesting mod, and if you proceed with it it would be interesting to see the benchmarks before and after the mod (e.g. you can use Xbench software). I should also point out that by doing this mod you will lose the warranty, most of the users prefer doing the upgrades after their warranty has expired.

In terms of the OS installation, you can boot off an USB memory stick of a sufficient capacity (e.g. 8GB and up) -- you need to use the Disk Utility to copy the image from the install DVD onto the USB stick and you can install the system. Unlike Windows, there are no "cd keys" for OS X, you just install it and it works (welcome to Mac). Alternatively there are several HDD clone software packages for Mac that could be used as well to copy the image off the OS.

written by Laz, January 11, 2010
I am about to change the hdd in a imac 24" was built in Sept of 2007.

at the top of the page you had this drive as a highly recommended choice:
Seagate Barracuda 7200.11 1.5 TB 7200RPM SATA 3Gb/s 32MB Cache 3.5 Inch Internal Hard Drive ST31500341AS-Bare Drive

is it still the ONE, you would recommend or there is another.
I just found your site, do not know how often you refresh it

Recommended HDD
written by Danny, January 11, 2010

Thank you for your post. The site is refreshed regularly -- the last comment was just a few days ago.

YES the 1.5TB Seagate is still the best buy - performance vs noise vs capacity relative to the cost. There are more advanced 2TB drives with 64mb cache available on the market today, but price wise I don't think it is worth it as of yet.

model numbers
written by anthony, February 02, 2010
your guide seems excellent and i'd really like to have a go at upgrading the HD in my current imac. however my imacs model number doesn't match exactly with the ones you have listed. it's a mid 2007 aluminium model with the number MA877B/A. is this the same as the one you have listed as MA877LL?
model numbers
written by Danny, February 02, 2010
Hi Anthony, yes, it's the same, the difference in the last letters only indicates your model is made for UK, this upgrade guide is applicable in your case as well. Danny
written by anthony, February 02, 2010
excellent! i'll order myself a 2tb seagate and have a go. thanks.
Thanks a bunch!!
written by Steve, February 04, 2010
Great instructions and useful comments. Took me about an hour on a 2007 24".

One small tip for those buying the Barracuda.
https://apps1.seagate.com/rms_af_srl_chk/rms_af_serial_check_index.jsp (on Seagate's site) lets you enter the serial number to see if there are firmware updates needed.
Upgrade HD without disconnecting display
written by Arjan, February 07, 2010
Just did an upgrade to a 2TB deskstar and noticed I could probably reach the HD without disconnecting the display (just like the "one reader" you mention in one of your updates).

I loosened all the screws and lifted the top of the display (left the bottom where it was) like a hood.
The I placed something between the computer casing (which remains horizontal) and the display. The space is about 3-4 inches, and was enough for me to remove the HD screws and bracket.
Then I popped off the HD connectors and took the HD took the HD out.

As I'm always a little hesitant with connectors I decided to give it a try and it worked great.

I guess it's up to personal preference.
Worked like a charm. Thanks!
written by Franko, March 01, 2010
I wanted to add my voice to the chorus of successful upgrades. Everything went very well!

Thanks also for the hard drive suggestion. I got the 1.5TB Seagate drive you suggested, and partitioned it into a 500 GB boot drive and 1T data drive. Some people mentioned the drive being noisy, but I find it whisper quiet.

A few interesting notes: My iMac came installed with Tiger, however I was able to completely reinstall the OS using the Snow Leopard Upgrade dvd I had purchased. The only downside was that iPhoto and iMovie do not come on the upgrade DVD. Fortunately I was able to install the missing apps from my original Tiger install DVDs smilies/grin.gif
Thanks a lot
written by Toby, March 03, 2010
It's really helpful, I just replaced the HD of my iMac 24" late 2007 model, can't believe I can make it. Thanks a lot! smilies/smiley.gif
early 2006 20” core duo? (not core 2 duo)
written by Gretchen , March 04, 2010
Hi, I’ve got one of those odd-duck early Intel core duos that was only made for about 3 months. It doesn’t have the glass front, looks almost identical to the prior non intel model, which makes me think I could simply follow Apple’s disk replacement instructions, BUT it does have torx screws on the bottom for all but the center memory slot. I don’t want to undo the torx screws only to find the cover won’t come off and I’ve left the speakers rattling loose internally or some such. Any suggestions welcome!
Early 2006 20” core duo?
written by Danny, March 04, 2010

Are you talking about iMac white? It is not an aluminum model is it? Perhaps you can google it and find what your model looks like and post the link here in order for me to understand what model you are talking about - then I'll perhaps be able to help.

Early 2008 3.06 Imac Memory and Drive Upgrade
written by Joe, March 09, 2010
Let me preface by saying Thank You for providing and maintaining such an informative site.
I use a 17" 2.5 Macbook Pro for mobile recording and 24" 3.06 Imac for my home studio, both on Leopard, with the Imac partitioned with Windows XP.
I came across your site while researching upgrading the 250gb/5400rpm drive in my Macbook Pro. I have completed that upgraded to a Hitachi 500gb/7200rpm drive.
Last year I purchased the 1.5TB Seagate that you recommend with intentions of using it as an external backup, but after reading this, what better place to use it than in my Imac.
After checking the serial number/frimware, I'm up to date and good to go. (Thank You Steve 2/4/10 comments)
The drive I will be replacing is partitioned and each partition is formatted differently. Partition 1 is OSX Extended (journaled) and has OSX Leopard and all my recording software, DAW's, samples, plugings, etc. and Partition 2 is Fat32 and only has Windows XP on it.
I was going to use Super Duper to clone the drive but a friend is telling me that won't work because the drive I'm cloning is formatted in 2 different formats. Any comments or work arounds?
written by Joe, March 09, 2010
Also, I purchased 4GB memory upgrades from OWC for both computers last year giving them the model numbers and relying on them to supply the correct memory. Using the About This Mac instructions above, I checked the newly installed memory in my MBP. Calls for 800Mhz....They sent me 667Mhz. The Imac calls for 800Mhz, but I assume they sent me 667Mhz since it was ordered at the same time. I still have to check the Imac to see what's actually installed.
After reading above, I'd like to upgrade to 6GB memory in both. I'll need one 2GB module one 4GB module but when I use your link to the 4GB module, it takes me to 4GB memory (2x2GB), not a single 4GB module.
OWC offers 4 2gb memory, but was wondering if you knew of another supplier?
Some say mixing 4 2 will slow the memory down. Is there any truth to this?
Thanks in advance for your reply.
Cloning FAT32 and HFS partitions on the same hard drive and 6GB iMac RAM memory upgrade
written by Danny, March 09, 2010
Hi Joe,

Thanks for sharing your experience with us! smilies/smiley.gif

What you might want to do is to manually partition the new hard drive with FAT32 (Windows) and HFS (Mac) partition and to use Norton Ghost Image to clone the Windows partition and Super Duper to clone the Mac partition.

Personally, I do not like hard drive cloning utilities, there is a number of things that could go wrong and the amount of time to make everything work properly might be staggering. For example, making a ghost image of Win XP, Vista or Win 7 will require re-activation (as an anti-piracy measure) as the OS will detect the hard drive has been changed(?)

What you might consider doing is performing a clean OS X install, then using Migration Assistant (Applications / Utilities) to move data from the old to the new hard drive (e.g. you can connect your old hard drive through an external USB enclosure). This will move your data AND software, music, plugins, everything -- practically there is no need to clone the Mac partition as Apple made this wonderful utility in the OS X that copies everything from your old Mac hard drive! And might I say perhaps reinstalling the OS X after a while as compared to hard drive cloning might get rid of a number of junk files that have accumulated throughout the years.

In terms of running Windows on a Mac - do you really need it on a separate partition? How often do you actually use Windows? If you do not have a need for a dedicated Windows machine you might consider running it from within OS X in a virtual machine, and this eliminates the need to have two partitions on a hard drive -- a single Mac partition will be all you need!

I personally use Windows applications through VmWare Fusion 3 virtual machine (another good virtual machine software is Parallels Desktop 5) that makes Windows run simultaneously inside my OS X. VmWare, as well as Parallels can copy your Windows XP partition into a virtual machine file (e.g. if you copy it from your old hard drive connected externally in an USB hard drive enclosure).

In terms of your experience purchasing the memory from OWC please note that mixing memory speeds is not recommended. Installing 667Mhz memory in an 800Mhz capable machine will slow it down.

In terms of the RAM memory upgrade of your iMac to 6 GB, I have updated the links above. You will need one 2GB 800Mhz SODIMM memory module and one 4GB 800Mhz SODIMM memory module to make the 6GB upgrade.

I hope the above helps! Good luck with your data migration and with the RAM memory upgrade!

routing the sata cable out of the imac alu case ( mid 2007 - 24'' )
written by jose Lima, March 18, 2010
Hi Danny,

I cannot stress enough the usefulness of this thread, thank you so much for all the info.

I have carefully read all posts ( I think! ) and whas particularly interested in the RAID 0 configuration with the two Momentus 500GB to get the theoretical maximum of 152 mps. ( 76mbs sustained data rate )

But my question is would it make sense ( or would it be possible ), to route the SATA cable out of the imac , with a high quality SATA cable to avoid interference, to a self powered RAID 0 enclosure with 2 seagates 1TB 3.5in ( 125mbps sustained data ) to get the maximum of 250 mps, lower the temperature inside the imac and increase the serviceability of the system and almost match the SSD performance?

Thanks again for all the info.

best regards

eSata port
written by Danny, March 18, 2010
Hi Jose,

Thank you for your accolades smilies/smiley.gif

What you are proposing is building an external SATA port - eSata. What you propose is feasible, however such project requires drilling a hole at the back of your Mac for the cable to come through - not sure if you want to do that. Perhaps if you have the skill set, you can install a true eSata connector at the back and make it look neat as well. If you succeed please let us know and send some photos!

Followup - Sucessful
written by Joe, March 28, 2010
Hi Danny,
Just a quick followup to let you know the HD swap to 1.5TB Seagate ended in sucess after a few problems.
I did not check the new Seagate drive before installing it and while installing Leopard had S.M.A.R.T report a fatal HD hardware error. I called Seagate support with my serial number - drive was still under warrantee.
I chose the ARO (advance replacement option US/Canada) where for $19.99 they advance ship a new drive post paid to and from you, but you must return the failed drive within 30 days or they will charge you for the drive. Once received, I checked and installed the drive, fresh installed my OS and everything is perfect.
The new drive is extremely quiet and runs cool.
Thanks again for your help.
Any advice on Tiger install
written by Wendy & Charlie, April 03, 2010
Hi Danny: Thank you so much for these excellent instructions. My son and I were able to replace our HD and upgraded our RAM -- with no problems, until we tried to install Tiger. (We used the 1.5GB Seagate and simply replaced our old RAM with your suggested 2GB Kinston Ram (to ensure that we would not have any instability issues) We have a 2007 iMac AL - that just had a HD failure. Problem is - when we inserted the disk to install Tiger - the computer started beeping 3x with a pause in between -then repeats. It won't allow us to move forward. Any ideas on how we might back track to figure out where we went wrong? Does it sound like a connection issue? I was a bit worried that the 2nd connector on the right hand side of the motherboard did not get seated properly. What does this connection do? Thanks so much!! Wendy
Three beeps means your Mac doesn't see any RAM
written by Danny, April 03, 2010

Three beeps means that your Mac does not see any RAM memory. You should make sure they are inserted correctly - perhaps you didn't push them deep enough into the slots (this is a typical problem as there needs to be a moderate force applied when inserting the ram memory). You might want to open the ram slots and reposition the two ram modules. If that does not work try inserting back the old memory and if that works perhaps something is wrong with your new memory modules.

If everything works well, the Mac should boot with its typical chime sound and a grey screen, following the start of OS X installation (if DVD disc is inserted).

Sweet post Danny!
written by Erik, April 25, 2010
Hey Danny,

Thank you so much. A year ago I read your instructions and upgraded my mid-2007 24" Imac EMC#2134 to 4G of ram. easy, cheap, fairly effective. Recently, my Imac has slowed to a crawl when using Lightroom, Photoshop, etc. I realized the problem is that I have filed the 500G hard drive to capacity with over 20,000 pictures. I read enough to find out that the internal drive should be less than 50% full to avoid a big slow down. I tried deleting unnecessary photos in Lightroom, and other junk, which was a good project on it's own, but with the terrible performance it was painstaking. I eventually got my drive down to under 80% capacity. No help at all.

I knew it was time to upgrade the hard drive. I have multiple backups of my computer, one with a newer G-safe using Time Machine, and I have used it with great success before, so the data issue was not my big concern - I didn't want to fry my machine! I have good mechanical skills, better than most, but it I was still hesitant.

Last night, I had enough, read the crap out of your post and others, and ordered the 2TB WD Caviar Green. I kept researching the drive options even after I ordered it, and started developing buyer's remorse. I read a detailed review of the WD green drive, and it seems to be an admiral performer, but against the better 7200 drives the green was definitely a performance trade-off. I guess the Pro for the green is the price and the lower heat. Performance was my problem [mostly space (lack of it) driven] and in my mind I didn't want to risk my $1500 system for an almost great upgrade. This morning I went to MacMall and bought a 2G WD Caviar Black 7200 64MB drive. Expensive ($281, $309 after tax), but I had no buyer's remorse at that point.


written by Erik, April 25, 2010
Here's my upgrade experience-

1. Home Depot for a Husky 8-1 torx driver with T6, T8 - I only needed T8 and a #2 phillips. Also at HD - suction cups and 2 cans of CRC duster. $21.
2. Make sure I had a good backup/mirror/clone of my drive. Check.
3. Laptop to access internet for directions check, help, etc.
4. Remove RAM cover.
5. Suction cups to pull off the Plexiglas. Check. Broke off one alignment tab, no big deal.
6. 12-T8 screws to remove the aluminum frame, disconnect iSight at top (plug). ***Note-make sure you pay attention to where the screws came from as there were 3 different lengths on my iMac (I'm sure this has already been covered)***
7. 8-T8 screws to free the monitor. (all the same size on mine)
8. I lifted the monitor carefully and looked at the connections. I decided that I did not have to disconnect any of them. With the computer on it's back, the top toward me, I rigged a jig to hold the top of the monitor (my end) up about 8" inches up and let the bottom of the monitor rest almost in it's original place. If that is hard to visualize, think of a book on a table, with the binding (bottom of the monitor) away from you . Lift the cover of the book about 30 degrees and support it while you work.
9. I carefully removed the foam over the temp sensor, took a while to not tear it up.
10. My sensor had a plastic piece that anchored it to the drive with adhesive. I carefully and slowly pried that off and it kept it's glue. The temp sensor was loose now, moved it aside.

My iMac was terribly dirty inside, blowing off the dust made a mess. I recommend having lots of dusting agent on hand, 2 cans so you can use a warm one with more pressure after cooling the other down by using it and lowering the effective pressure. You will really want this for the monitor and glass before reassembly.

11. I removed the drive, unplugged cables, swapped drive mounts, plugged cables, reinstalled drive, replaced temp sensor, replaced cover for temp sensor (enough glue still to hold well), added scotch tape for more security, put foam cover back over temp sensor. Original drive also had an adhesive pad which I put in the same place on the new drive.
12. I put monitor back in place (carefully) with 8-T8 screws. Re-attached iSight connection and installed aluminum frame.
Dusted the crap out of the monitor and glass.
13. Replaced glass, plugged it in, turned it on, prayed.
14. Drive noises, gray screen. Good. Inserted install disk and installed Leopard. Good.
15. Attached G-safe and restored everything (379 Gigs) using Time Machine in about 2 hours. Good.
16. Restarted computer, start-up was noticeably faster. Looked around, everything seemed fine. Opened Lightroom to stress it out with my RAW files. Went to the folders that really made we want to cry. Everything worked like this iMac came out of the box with an empty hard drive! Unbelievable!

I'm a few hours into my "new" computer, so all I can say is it works like new. Maybe better. I don't know if I would have been as happy with the green drive, maybe so. I suspect that installing Leopard new and then importing preferences, files, applications, etc. with my Time Machine backup could have cleaned things up quite a bit. But I do know that I have a big fast drive, and I could not be happier with the performance. I plan on keeping this drive under 25-30% capacity and i hope it keeps rocking.

Thanks Danny for the post. I know there are several others posting similar information, but you seem to be the first and the best. And you continue to provide help and updates - very nice.


another thing
written by Erik, April 27, 2010
My only concern after the install was heat with the new high performance drive in a tight iMac enclosure. I downloaded a free program, Temperature Monitor to check my temps. I found I was already near the threshold of my WD drive (running at 58 deg C). I installed smc fan control and boosted my fans. Now my iMac is at 41 deg. c. and my new drive is at 51 deg. c. while I'm using it. the caviar black drive is at 46 deg. c. while idle. The fan on my external drive is still louder than my iMac fans after I turned them up a bit.
Kernel Panic-Help Please Now What??
written by Justin , May 01, 2010
So I followed all the same steps as Eric.
installed Western Digital Caviar Green 1.5 TB (SATA, 64 MB cache, up to 7200 RPM)
Migrated from time machine (about 2 hours)

Went to restart and got kernal panic. can't seem to get beyond it at this point.
have tried option key
have tried to reset pram...nothing, still getting the kernal panic every time.
here's whats happening.
1. press power button on back of computer.
2. chime rings.
3. apple appears on gray screen.
4. os x install disk begins whirring in optical drive.
5. screen shifts to dark gray with message "you need to restart your computer"

Upgraded to 2TB WD20EARS (iMac 2008 - 24" MB325LL)
written by Momu, May 01, 2010
Thanks a lot Danny for the detailed steps, I upgraded to 2.0TB used Western Digital WD20EARS, it was smooth.

I was afraid of pulling the protective cover of the LCD, but it was fairly easy, I just used the 3 x household suction clip, it came out smoothly.
Re: Kernel Panic-Help Please Now What??
written by Danny, May 02, 2010
Hi Justin,

It seems to me that everything is OK with your hard drive upgrade, hardware wise, as you were able to install OS X. You experienced problems after the time machine restore. Kernel panic means that the base of the operating system is having issues with some software drivers installed. Therefore, I believe that your problem is software related.

I would suggest to insert the install DVD into your Mac, restart, hold the Option key immediately after the chime sound - which will allow you to select boot from the DVD drive. Run the clean install again (use Disk Utility to format the drive clean). Now you are back at square one with having a clean OS X installed.

In terms of the backup machine restore, start the Migration Assistant (in Apps Utilities), and do *not* select restore of software or configurations - just the personal user data. This will mean that you will need to manually install all of your software once the restore of personal data is complete, however this is necessary in order to avoid copying back software with which your Mac has issues. It is a hard and lengthy procedure to detect which particular software component is giving you trouble, I believe the suggested procedure is the most efficient workaround and solution on your case smilies/smiley.gif

Re: Thank you for sharing your upgrade experiences :)
written by Danny, May 02, 2010
Hi Erik and Momu,

Thank you for sharing your upgrade success experiences with us smilies/smiley.gif

Much appreciated
written by Steven, May 03, 2010
I followed this guide to upgrade my 2007 alu 24" iMac and just wanted to post a quick note to let you now how much I appreciated your guide.

I managed to install the drive without talking the LCD out completely, I just unplugged the small (temperature) cable and left the other two in place. It's a little harder, but still manageable.
Thank you
written by Barrett, May 10, 2010
I was able to replace my dead drive in about an hour's time and am now restoring from Time Machine backup. Thanks for the great guide - ~$100 for a drive is much better than ~$1200 for a new iMac!
communication technology teacher
written by Daniel, May 27, 2010
I have the intel 2core duo imac. the one just before the metallic version. can i still use this upgrade or is the inside different? What about the video card? Specs for overheating...?
re: iMac white
written by Danny, May 27, 2010
Daniel, this upgrade guide is for aluminum iMacs, however somewhere above in the comments there are few links for iMac white upgrade, just search for it (or use the browser's search function). Good luck. Danny
Thank You Soooooo Much!
written by Chris Craig, June 05, 2010
Wow! Our iMac 24 2007 losing it's disk could have been totally catastrophic if it wasn't for a few redeeming factors:

We had a Time Machine backup.
Our local PC World had a good stock of WD Caviar Green 1TBs.
Our local Maplin had a mini Torx set.

However, the key thing was finding this article which made it all possible.

What a gift to the iMac community! Many many thanks...


17hrs left to restore, however....
written by Dinyar, June 17, 2010
The entire procedure is so throughly presented, wow!
I am 65 years old and would never have dreamt of doing this but after going through the procedure that you have presented several times I am going to attempt it. Do hope that my fingers are steady enough to be able to complete it correctly. Thank you for making me feel a lot younger to undertake this adventure.
I shall let you know how it went off.
written by Miles, June 22, 2010
Awesome guide, really. Thanks a bunch for this detailed walkthrough and everyone's contributions. If you're reading this page for the 1st time, everything you need to do this successfully IS ON THIS ONE PAGE smilies/smiley.gif

I did my installation without disconnecting the iSight or the Screen. Just make sure you have a nice big workspace to do so.
problem with screen unless connect to a 2nd screen
written by Cyrus, July 07, 2010
bought a used i mac 20 inch (200smilies/cool.gif everything works if we connect the computer to a 2nd monitor. it works even the 2nd monitor is not plugged in. am not sure what the problem is. could it be a bad video card? appreciate any help. Thnx

written by G. Belk, July 07, 2010
I'm gathering all the information I can about upgrading my (bought new) Feb 2008 24" iMac but in the 2008 models you show I don't see my model. Mine is MB 322 LL/A. you start at 323 324 & 325. Will all this still work on my iMac? Looking to put in a 1TB WD Caviar Green. Also noted that the iMac box shows the ram is 667 not the 800. Will the 800 memory chips work in my unit? Other than that I'm game as my iMac's SMARTreporter shows an impending hard drive failure. So sloooow I could build a new machine in the time it takes from one click until it's ready to receive another click from me...boring.... July 7, 2010 10:22AM MST.
LCD not working
written by Danny, July 11, 2010
Hi Cyrus, there are number of things that could be related to your problem with LCD not displaying anything - the graphics card, the LCD itself, the backlight, inverter (power for the backlight), power to the LCD, etc. From what you are saying it does not seem that the graphics card is fried - it does produce output on a second monitor. I am more inclined to believe something around the LCD (inverter, power), or the LCD itself need to be checked. It is difficult to check all of these things without proper diagnostic tools. Best recommendation that I can give you is to take the machine to an authorized repair center for them to take a look at it. Danny
written by Danny, July 11, 2010
Hi G. Belk,

This guide will work for ALL iMac aluminum models, your model MB322LL/A included as well! Your model MB322LL/A from what I can gather is a custom edition with an Intel extreme processor. You can use this guide with your machine, no worries. 1TB WD Green seems like a good choice for quiet and cool machine.

Your machine is a bit older model (2007), that is why it is using 667Mhz RAM instead of 800Mhz RAM. The 800Mhz memory will work in your machine (backward compatibility), but this is not recommended, you are better off getting 667Mhz memory for it. Just check out the iMac memory upgrade guide for correct modules for your machine.

Encourage everybody !!!
written by egoist, July 18, 2010
Thanks a lot for this page. I will encourage everybody to rip off their imacs. I did a 1.5 Terra update un my early 2008 3.02Ghz iMac, because my hard disk showed that it was broken (still working, just the file system) and i cannot fix it by system-tools. So i did the rip-off (thanks for the great pics) and guess what... my HD-temp-sensor was loose. Old-Temps were HD:60C and up, CPU 60C and up after 30 min. running.

Now: changed the HD, fixed the sensor (i love duct-tape!!! or Gaffa!!!), now copying my backup from two external disks to the internal and temps are: HD 40C / CPU 51C (running for right now 30 min. and not finnished yet) - Conclusion: RIP YOUR MACS, AND CHECK THE CHINESE ASSEMBLERS WORK. Their not as good as European or US workers... hehe.
TLOP error solved in my case
written by JR, August 28, 2010
I too performed this upgrade on my 2007 20" imac, and when I re-assembled, the fan speed went to 3500rpm and stayed. I searched for over a year trying to find a solution, and then in June or so I stumbled upon a hint that it was the LCD sensor cable. I opened my imac up again, and found lo and behold that my lcd sensor cable was frayed where the lcd met the fan casing! I bought a used one pulled from a mac online, and lo, installed it and my fan is now operating normally!

To the person that had the tlop error, check your lcd sensor cable and see if it is frayed.

replace superdrive with HDD?
written by David, September 07, 2010
Hello, I was thinking about changing my dead superdrive in iMac alu late 2007 by a 2.5" drive as it is possible to do for macbook.
Is it even possible? I did not find any answer for this...
Thank you
written by Jeff, September 08, 2010
Hi, it is now almost impossible to find any SATA hdd with SATA II in the market. Can I use SATA II?
Installing secondary hard drive instead of superdrive
written by Danny, September 08, 2010
Hi David,

Yes, you can replace the superdrive in your iMac with 2.5in SATA II hard drive, however you would need an adapter called OptiBay (12mm version with SATA connector) or many substitutes available on the market, just google for it.

In addition, for all MacBook, MacBook Pro owners, it is also possible to replace the superdrive with a secondary 2.5in SATA II hard disk, however these use slimmer superdrives, so you would need 9.5mm SATA version of OptiBay adapter.

written by Danny, September 08, 2010
Hi Jeff,

There seems to be a bit of a confusion in the market (and the text above as a consequence) on how terms SATA, SATA I and SATA II are used. Generally accepted terminology would denote SATA as just a connector -- type of a plug available on a device regardless of its transfer speed, whereas SATA I would denote device capable of 1.5Gb/s transfer speeds, and SATA II would denote device capable of 3Gb/s transfer speeds. To make the confusion even greater, some manufacturers use terms SATA 1.5Gb/s and SATA 3Gb/s to describe SATA I and SATA II products respectively.

All recent Mac computers (I believe even since 2006, 2007) use SATA II hard drives (the faster ones), therefore you would be all set with purchasing a SATA II device for your iMac upgrade smilies/smiley.gif

HDD format with 10.6?
written by Vic, September 11, 2010
Planning on changing HDD tomorrow since a grey screen comes down after a couple of minutes of the computer running (iMac 2008, 24", 500GB HDD). Will replace with a 1TB HDD, but wanted to know if I can install OS X 10.6 (snow leopard) directly instead of installing 10.5 (leopard), then upgrade with 10.6? Thanks for the guide and everyone's suggestions
Installing SL
written by Danny, September 11, 2010
Sure, you can install Snow Leopard (SL) 10.6 right away if you have the retail DVD.

On the other hand if your DVD is the upgrade version of 10.6 then you most likely will have to go 10.5 then 10.6 route.

written by Frank, September 13, 2010
Thanks, it worked like a charm.
Seagate Barracuda Low Power Hard Drive, 2 TB, SATA, 5900 RPM, 32MB Cache
written by mark, September 23, 2010
Hi want to do this upgrade

will this drive work on my intel mac ali 2007
Seagate Barracuda Low Power Hard Drive, 2 TB, SATA, 5900 RPM, 32MB Cache

thanks mark
written by Danny, September 24, 2010
Mark: Yes. Any SATA 3.5" hard drive will work in your iMac 2007, including the drive you're mentioning.
4 7,1s to upgrade, pre-purchase questions
written by John Byrne, September 27, 2010
Firstly, Danny.... A W E S O M E job! You are inspiring me to donate my time in doing tutorials of my own, some day, and on another topic ;-)

Wondering if I can run a few things by you:

1. Can I install an SSD in the superdrive bay? Is this a good idea?
2. 6GB RAM in all machines (Mid-2007 7,1 20" 2mhz and 24" 2.4mhz) using same latency and brand RAM, correct?
3. Can I also install an SSD in place of the original HD?
4. Can I stripe then, then mirror them to a FW800 external Raid 1?
5. Can I use the FW 800 plug to run that, as well as a boot drive for the OS and programs?
6. Is it overkill to install the SSDs? If I wanted to stripe the two HDDs inside the iMac (3.5 & 2.5), is there a compatible pair that would work together well?

I am basically trying to edit video. I am using PPCS5 on the 24" 7,1 on the original factory HD and only 4GB of ram. I feel this machine about to implode on me.

The other three iMacs have barely been used. I wanted to make two more workstations, say one for captures and renders, and other for rough edits done while other machines are running. So, this would apply to all machines.

Thanks for any help, and if you don't respond, I wouldn't blame you ;-)

SSD in iMac
written by Danny, September 27, 2010
Hi John,

First of all thank you for your commendations! Please do consider donating a bit of your free time to the Mac community, that is what is making it so strong! smilies/smiley.gif

In terms of the questions you have - a general answer to all of them is that it is possible to do all of those things you are wondering about.

However, if it is a good idea or not depends on the machine usage, hence your description of what do you want to do with the machine is the most helpful.

First of all, you need to determine if it is really the disk speed or CPU power that will make the difference in your circumstance. You should install iStat, or one of those system monitoring utilities in order to monitor disk transfer speeds and CPU usage WHILE you are actively editing video, and you should do this for at least couple of days, to make sure your conclusions from this empirical test will be correct.

If what you do with video is using the hard drive a lot, then installing a single SSD hard drive instead of the original drive will help a lot. Installing another SSD hard drive (with the appropriate OptiBay adapter) instead of the DVD and configuring them in striped RAID mode, will additionally boost the hard drive performance to the maximum possible.

On the other hand, if the system monitoring utility shows your CPU is maxed out while editing video, then you should really consider switching to a more powerful machine, such is one of the Mac Pro models (e.g. with 8 or 16 core processing power!).

In terms of one or two external hard drives and configuring them in a mirror configuration, that is theoretically possible, although I haven't had a personal experience with it. Another issue to consider is also the total cost of ownership. Also, please note if you are making a striped RAID, ALL hard drives should be of the same size.

Therefore, your main objective is to determine if you need more CPU power, or if you need a faster hard drive performance. If it is the CPU speed you need, then you need to switch to a more powerful machine. If it is the hard drive speed you need to boost to the max, then your route of upgrading might be as follows:

1. Replace the original internal hard drive with an SSD drive
2. If that is not sufficient, then you can add another SSD drive instead of the DVD drive (with OptiBay adapter) and configure them as a striped RAID (you will need to boot the system off the DVD and configure drives in striped RAID model with DiskUtility as soon as you boot off the Snow Leopard DVD). Please note that the second SSD drive must be of the same size as the first one!
3. Finally, for the backup, you can simply go with a Time Machine setup on an external firewire 800 drive. I don't believe that installing two external hard drives (of the same size) and making a backup mirror RAID (in addition to striped RAID) will make much of the difference because firewire 800 ports are slower than a true SATA connection. Therefore just having a huge external storage system on the firewire 800 and configured with the Time Machine might be just what you need.

Good luck! smilies/smiley.gif

Upgrade Done In 40 Mins Thanks
written by Mark, September 30, 2010
Well Dan,

I just wanted to thank you for this post.... Upgraded from a 350 gig hard drive to a new 2Tb one

I followed the instructions, but only removed one connector for the screen on the right hand side, i listed the screen up and propped it up with a book, put my hand i and removed sensor and power and hard drive cable pressed and released hard drive cradle and its was out .....!

I took the case bits off the old drive and replaced i super glued the plastic sensor housing .

All went back easy ... never took isite connector off just propped it up

Thanks again saved $400 that someone wanted to do this at my local pc shop.

thanks mark

New Drive won't boot
written by Rob, October 07, 2010
Thank you for the great tutorial, found it very helpful and easy to upgrade the drive.

I got a WD 1TB Cavier Green, the first one I installed the computer would boot-up but did not recognize the drive. Opened it back up make sure everything was still connected properly and it was; so I exchanged that drive for a new one. Now after I turn on the computer it remains in a white screen and continues to try and read the bootup disk, can't get it to eject the disk or to go past the white screen.

Any Suggestions?

Thanks Rob
New drive won't boot
written by Danny, October 07, 2010
Hi there Rob,

Thank you for your post!

When you install a new drive it does not have an operating system installed on it and the normal thing is for the computer to display a grey screen with a question mark on it - as pictured below - prompting the user to install an operating system on the new drive. Therefore if you have this on the screen everything is quite normal (the computer is just complaining that there is no OS installed on the new hard drive):

If you do not have the above on the screen, then something else might be wrong with the computer, you have to retrace back your steps, perhaps a cable not inserted properly or some other technical issue, or even accidental damage during the installation...

If you do have the above screen with the question mark on your computer, then you would just need to insert OS X installation DVD disc into your computer, boot off it - by pressing and holding the OPT key following the chime sound you can SELECT the device you boot from - in this case the DVD.

If you would like to eject the DVD disc, following the boot chime, just hold the left mouse button and it will force-eject the DVD from the superdrive.

Other than that, if it doesn't work and if you are unable to get it going, I would advise seeking local technical help.

Good luck! smilies/smiley.gif

written by Rob, October 07, 2010

Thank you for the quick response.

I am getting only a grey screen without the question mark. the first drive I tried I got the question mark but the computer did not recongnize the drive as being installed at all. So now with trying a third new drive it is all working properly. Thank you again.

You're welcome
written by Danny, October 07, 2010
Hi Rob,

I'm glad that everything worked out well for you!

written by Aharon, October 15, 2010
Thank you Danny

great guide. followed it and have a few things to add:
1. used only one suction cup at one corner for the glass. easy!
2. had a few screws holding the LCD in place. after removing them, the rest was exactly as described.
my original WD 320 GB failed on me. installed a SEAGATE 1.5 TB.
my iMac 24" is up and running better than new!
Worked Great!
written by Kris, October 18, 2010
Excellent instructions! It took me about 40 minutes to replace my tiny OEM drive with a 1.5GB WD Caviar. I then booted with my Leopard upgrade disc, partitioned the new drive, and used Time Machine to restore my data. Everything works like charm. Thank you!
written by Eric, November 07, 2010
Hi Mate!
First of all, thanks for sharing your experience and knowledge. Following your advice, I have upgraded my HDD to a Seagate Barracuda 1.5To, and the result is great, both from a performance and noise POV.
Note that , in my experience, it is not necessary to detach the display power connector as explained in step #4. you can just lift the display up, rotate it anticlockwise and leave it put. This will make the HDD accessible and you can work from there.