Mac-toting SSD users won't have to wait until OS X Lion for TRIM support, with the news that last week's OS X 10.6.8 update - expected to be the last of the public Snow Leopard builds before Lion roars onto the scene - already adds in the feature. MacRumors spotted the the change, though right now it's not entirely good news for every OS X user with an SSD.
That's because Apple has only enabled TRIM support for Macs with its official SSDs, rather than for third-party drives. So, if you've swapped out your original hard-drive for an SSD rather than pay the somewhat hefty upgrade charges to Apple in the first place, you won't get TRIM. Apple had actually enabled the feature in a custom build of OS X 10.6.6 for SSD-equipped early 2011 MacBook Pro models, but now its been extended to all those with official solid-state drives.
TRIM is basically an automated garbage collection system for SSDs, feeding information back to the operating system from the drive as to which data blocks are no longer in use and as such can be wiped. Without it, drives can become progressively more sluggish. Although Windows users have enjoyed TRIM support for some time now, Mac users have had to do without - or pick up one of the SSDs which has its own system of garbage collection, such as some from OCZ's range.
As TRIM is a part of the SATA standard, there seems to be no reason beyond self-interest for Apple to limit support to only its own SSDs. Hopefully the company will have a change of heart by the time OS X Lion arrives.