This is by far the best ‘bang-for-buck’ modification you can perform on your iMac. Well, apart from putting in lots of RAM. Best of all? It’s a very simple and straight forward procedure that takes approximately 25 minutes to complete.
I won’t lie, I was actually talked into upgrading to an SSD by several friends, the only problem was cost. Last weekend I decided to finally bite the bullet and purchased a 120Gb Intel 320 Series drive. I highly recommend doing your research before going out and buying just any drive as all drives are susceptible to problems, some just less than others. From the research I did, it seems the Intel drives are a great middle ground in terms of reliability and performance.
Prerequisites
Firstly, Whatever SSD you do end up purchasing, I suggest that you find out if you need to update it with a more recent firmware as not all SSD’s ship with the latest one available. For instance, I upgraded to the latest 320 Series firmware as it offered a fix for a certain issue which occurred with power loss.
Secondly, assuming you have purchased Mac OS X Lion, you’ll need to create a Lion Install on a USB key, see the following guide on how to do this: http://www.cultofmac.com/105527/how-to-make-a-bootable-install-disk-of-mac-os-x-lion/ Otherwise, have your Mac OS X Install DVD handy.
And finally, be sure you have Torx T8 and T10 screwdrivers handy.
Step 1a: Opening up the iMac
This is much, much easier than you think. I’ve read some articles online making out that opening up your iMac requires you to have a degree in engineering or that it was a real terrifying ordeal.. well, it’s not. I’m not sure if the people suggesting it was were just big girls, or that Apple themselves sent some emails trying to deter people from doing it, either way it’s a very simple and straight forward process. The easiest way for you to open up your iMac is to follow the visual guide over at iFixit: http://www.ifixit.com/Guide/iMac-Intel-27-Inch-Hard-Drive-Replacement/1634/1
Tip: Don’t spend money on any suction cups to lift the glass off. Just buy a roll of thick duct tape and press it firmly onto a corner. Gently (but with some force) pull it towards you and you will notice it detach. Then simply slide your finger all the way across the top in between the bezel and glass to detach it away from the magnets.
Step 1b: The HDD temperature sensor
If you’ve followed everything in the iFixit Guide and all went well, you’re probably wondering at this point what you’re supposed to plug the HDD temperature sensor back into? Well, here’s the thing; you don’t. What you actually need to do is to trick the sensor into thinking everything is fine. You may have done some google searches and read posts about “shortening” it, relax.. it’s not as crazy as something you’d see on MacGyver, although this is a MacGyver style workaround.
I wanted to elaborate on this step and help others out with it visually, as I myself read about it on several forums but noticed that no one posted any pictures of how they done it, and I certainly wasn’t going to pull my iMac apart just to see what I needed to do. All you need to complete this procedure is a small, thin piece of wire.
I used a small piece from a metal twist tie (the ones you find wrapped around cables to keep them neat) which is pictured here, bent into a ‘U’ shape. What I then did was put it into the connector as pictured here, matched up with the wires. After that, I simply cut a thin piece of electrical tape, covered the wire and tucked the cable neatly under the others near the temperature sensors.
“Why do I have to do this?” you might be asking. Well, if you don’t follow the above procedure, your HDD temperature sensor will panic thinking something has gone wrong and consequently the fan will run at a noisy ~5000rpm+ as opposed to a quiet ~1100rpm.
Tip: Before putting the glass back on, turn your Mac on and ensure that the temperature sensor trick is working. If a loud ‘whirring’ type of sound is heard, it isn’t.
If you’re still not comfortable performing this trick, I suggest you look at a software solution. Perhaps something like http://www.hddfancontrol.com
Step 2a: Installing Mac OS X
By now you should have your Mac OS X Install DVD inserted or Lion Install USB Key plugged in with your Mac preparing to begin installation. The first step is to format the SSD using the Disk Utility, the format I always use is Mac OS Extended (Journaled). Once this step is complete, you can begin installing Mac OS. Depending on the speed of your system, this should take ~20 minutes.
Step 2b: Enabling SSD TRIM support
Once the install has been completed and you’ve set up your Mac, the next important step to take is to enable TRIM support on the SSD. By default, this will always be disabled as Apple has only enabled this command for their proprietary supplied SSD’s. The good news is that with a few commands from within the Terminal, we’re able to enable TRIM on 3rd Party SSD’s.
The TRIM command allows an operating system to inform a solid-state drive (SSD) which blocks of data are no longer considered in use and can be wiped internally. For an in depth look at TRIM, see: http://www.tuaw.com/2011/03/27/keeping-ssds-in-trim-doing-the-math/
To enable TRIM, use the following commands in Terminal:
1. Backup the IOAHCIBlockStorage file that we’re about to patch:
sudo cp /System/Library/Extensions/IOAHCIFamily.kext/Contents/PlugIns/IOAHCIBlockStorage.kext/Contents/MacOS/IOAHCIBlockStorage /IOAHCIBlockStorage.original
2. Modify the IOAHCIBlockStorage file to enable TRIM support for all SSD’s:
sudo perl -pi -e 's|(\x52\x6F\x74\x61\x74\x69\x6F\x6E\x61\x6C\x00{1,20})[^\x00]{9}(\x00{1,20}\x51)|$1\x00\x00\x00\x00\x00\x00\x00\x00\x00$2|sg' /System/Library/Extensions/IOAHCIFamily.kext/Contents/PlugIns/IOAHCIBlockStorage.kext/Contents/MacOS/IOAHCIBlockStorage
3. Clear the prelinked kext caches:
sudo kextcache -system-prelinked-kernel
4. Clear the System kext caches:
sudo kextcache -system-caches
All these commands should provide zero error outputs if done correctly. After the 4 steps have been completed, reboot your Mac!
To check if your SSD is now TRIM enabled, open up About This Mac, click on More Info and then click on System Report. Within System Report click on Serial-ATA and next to TRIM Support it will either say Yes or No.
All done, enjoy the speed!
Note:
I’ve readI can confirm that performing Software Updates will disable TRIM support. To re-enable it again, simply follow the steps above.
In the case of something going wrong and you need to restore the original IOAHCIBlockStorage file, use the following command:
sudo cp /IOAHCIBlockStorage.original /System/Library/Extensions/IOAHCIFamily.kext/Contents/PlugIns/IOAHCIBlockStorage.kext/Contents/MacOS/IOAHCIBlockStorage
