Apple has made modifications to the 2011 iMac which essentially prevent people from doing third-party upgrades to the main hard drive, according to upgrade vendor Other World Computing. The flaw is said to lay with the SATA power connector for the main bay, which has switched from a 4-pin configuration to 7-pin. In combination with proprietary Apple firmware on stock hard drives, the special power cable helps to control fans which regulate drive temperature.
