iMac Hard Drive Replacement

My trusty 2011 27” iMac had been running slower and slower recently  Nothing I did seemed to help, including a nuke and pave of the operating system (which had been upgraded in place from Lion to Yosemite).  It having shipped with an oh-so speedy 1 TB spinning drive, the first thing I checked was the SMART status of the hard drive.  It reported that it was fine, until the day it didn’t.  Awesome!

Luckily I’ve been a Crashplan user for years and I used Time Machine for local backups.  Unluckily, the Time Machine drive got disconnected back in April and no one noticed.    The OS on the failing drive booted, and my data seemed to be intact (though is it REALLY?  I didn’t check every bit and byte of every file) however the drive was borked enough that a new Time Machine backup wouldn’t run.  It would start and then set and spin and never progress nor finish.  I luckily I had a 3 TB USB drive with plenty of free space, so I downloaded the free trial of Super Duper and after a couple failed attempts it successfully backed up the User directory, which is what I really cared about.  After I verified the disk image contained valid data by opening it on a different Mac, I powered off the iMac and waited for parts to arrive from iFixit and Amazon.  Between Time Machine being present but a couple months out of date, a disk image of the failing drive, the working-but-failing drive itself, and Crashplan, I knew I could get my bits of data back from one source or the other.  That said, it was a hassle.  Plans are in place for a revamped backup routine, look for a future blog post about it.

I ordered the kit from iFixit for my model iMac.  I also ordered the following from Amazon:

The tools showed up from iFixit and the parts showed up from Amazon.  After reading and re-reading the iFixit guide, watching Youtube videos, and a lot worrying and fretting about breaking my iMac, I finally bit the bullet and took the thing apart.  I was much too involved in not messing up the machine to take proper pictures, but that wasn’t the point anyway.  iFixit has terrific pictures of the process, you can look at better pictures there than anything I could have taken.  I got everything apart without issue (with the help of my lovely wife), and even managed to get everything back together and only losing a screw for the panel into the guts of the machine once.  But the last piece, the big piece of glass, wouldn’t fit back on.  On the top, in the middle, it wouldn’t snap back on completely.  It was fine at each top corner, but the middle was bowed out a good inch or so.  It eventually occurred to me, the glass won’t go back together in the middle, which is where the hard drive is.  Perhaps the adapter I linked to above is too tall and is sticking out?

So I placed a second order on Amazon for this: Newer Technology AdaptaDrive 2.5″ to 3.5″ Drive Converter Bracket.  It’s essentially a low profile 2.5” <-> 3.5” drive adapter.  It arrived, I took the iMac apart (again) and swapped adapters.  I’m happy to say the machine went back together this time just fine, no issues whatsoever.  The second time around the process went much faster since I knew exactly what to expect.  The iMac is now blazing fast with the SSD compared to what it had been even with a healthy spinning HDD.  One thing I was concerned about was the fan noise after replacing the factory drive.  Evidently the HDD from Apple contains Apple provided firmware that reports the temperature of the drive.  If you replace it with a drive that doesn’t have that, you end up with a computer that runs the fan at 100% speed 100% of the time.  Noise aside, that sort of treatment is bad for the fan and will eventually destroy the bearings in it.  I ordered the OWC temp sensor that I linked to above.  It sticks to the top of the replacement drive and plugs in-between the SATA port of the drive and the plug coming from the motherboard.  At $40, it was an expensive component but it is working flawlessly.  That is a much better option than just letting the fan run continuously or loading some 3rd party no name kernel extension to allow you to control the fan via software.