
So this basically means you can use standard 3.5" SATA 3.0 or 6.0 Gbps SSD drives, but you will have to do some tinkering and possibly get a connector like this one, in order to avoid issues.
SOLID STATE DRIVE FOR IMAC 2011 INSTALL
I want to use an external SSD drive as startup disk to extend the life of my beloved iMac. Im currently looking for the 2011 iMac, so i can install an SSD and use the optical bay for a HDD. Now it runs at snail pace and spinning beachballs abound. I’ve maxed the memory but it’s been running slower and slower over the years but it was still tolerable until I updated to Big Sur 11.6.


However, creative hackers no doubt will continue to find ways around whatever limitations are in place whether using software methods, hardware methods, or a combination of the two. I have a iMac 27 5K Retina Fusion drive (late 2014). That it has become even more difficult to upgrade the hard drive in the "Mid-2011" and "Late 2011" iMac models with a layer of software complexity certainly is unfortunate. Ultimately, it is possible to upgrade the hard drive in the 21.5-Inch and 27-Inch Aluminum iMac models or upgrade or install a secondary SSD in the "Mid-2011" 21.5-Inch models and "Mid-2010" and "Mid-2011" 27-Inch models, but just opening the case is a challenge and it is definitely not for the faint of heart. This site has extensive information on the issue and warns:

From our testing, we’ve found that removing this drive from the system, or even from that bay itself, causes the machine’s hard drive fans to spin at maximum speed and replacing the drive with any non-Apple original drive will result in the iMac failing the Apple Hardware Test (AHT). Hard drive temperature control is regulated by a combination of this cable and Apple proprietary firmware on the hard drive itself. As you write, Apple seems to have undertaken some effort to make replacement of the internal HDD difficult, as described here:įor the main 3.5″ SATA hard drive bay in the new 2011 machines, Apple has altered the SATA power connector itself from a standard 4-wire power configuration to a 7-wire configuration.
