Apple Disables Trim Support on 3rd Party SSDs in OS X
hothardware.comI don't think this is Apple trying to be difficult: SSD TRIM is buggy between all the different vendors (today even Ubuntu enables it only for Samsung and Intel SSDs by default), they want to guarantee that it works by whitelisting what they ship with, and the mandatory driver signing seems like a security improvement. If some third party wants to ship a signed kernel extension that works with their specific SSD (or generic ones, even) and supports TRIM, that should be possible.
FWIW, there is a third party SSD drive that works with Apple's default drivers for TRIM support; I suspect they're doing some sort of identifier spoof to fool the whitelisting code: http://www.angelbird.com/en/prod/ssd-wrk-for-mac-929/
Does this whitelist drives that report themselves as a manufacturer of "Samsung", or does this whitelist drives that report themselves as "Apple".
If it's the latter, then they've functionally prevented me from ever upgrading a computer that I've purchased from them to add a new, larger hard drive. Now I cannot purchase a Samsung SSD from a third-party and have TRIM support (despite the fact that they ship the same drive, only changing the name reported as the manufacturer). Worse, a cursory glance at the store suggests that they don't sell SSDs as accessories, so I can't upgrade my drive at all and get TRIM support, even at crazy high Apple markup.
(I didn't find this advertised, but I suppose it's possible that the Apple Store may do this upgrade themselves, it seems totally crazy that Apple would completely prevent me from upgrading my disk.)