Do-It-Yourself: Upgrading Apple's 27" iMac With An SSD
Apple’s iMac is a great machine. Unfortunately, upgrades for it are expensive, particularly if you want an SSD. Currently, Apple charges $500 for a 256 GB solid-state upgrade. A 256 GB Samsung 830 SSD only costs $290, and a Crucial m4 can be found for even less (under $250, even). And both prices include free shipping.
Today, we show you how to enjoy the added performance of an SSD on your 27" iMac without breaking the bank, so long as you're willing to put in a bit of work. Remember, though, doing this voids your warranty, and we aren't responsible if something goes wrong along the way.
One more comment before we get started: our iMac’s fan continuously ran at full speed after we swapped out its drive. This is due to certain firmware hooks that allow OS X to read the drive’s sensor data without involving its SMART attributes. This problem can be taken care of with fan control software.