I've just put a SanDisk Extreme 240GB in my new MacBook Pro running OSX Lion. Now I'd like to know whether I should use TrimEnabler to enable the TRIM function or not.

  • @MaxRied What does fsck -ff do that fsck -f does not do? Also, why would you recommend -y? Googling turned up this explanation of that parameter: "Assume a yes response to all questions asked by fsck. This should be used with great caution as this is a free license to continue after essentially unlimited trouble has been encountered." Jun 26 '12 at 16:43

Since the enabling of TRIM support in OS X Lion for 3rd party drives is strictly unofficial, it's really your own choice.

Though I would recommend to enable TRIM, as tests have shown that it does really work. (Low-level inspection of written blocks in Linux).


That SSD does have on-board garbage collection, it seems, so depending on how well that works you may not need to enable TRIM. With some drives, the performance can decrease significantly before garbage collection kicks in and in that case, you may want to enable TRIM.

It is an unofficial 'hack', so you may want to consider that as well, and you'll have to re-enable it every time there's a new update to the OS (and hope it still works). I do use it with my older Corsair P128 and haven't had any problems with it.

  • 1
    Some more info: OWC, whose SSDs uses a SandForce controller like SanDisk does, recommends not enabling TRIM for their SSDs.
    – David
    Jun 25 '12 at 19:06
  • 1
    IMO there is an almost tangible sense of "CYA" to that OWC blog entry on TRIM. Also, it was written nearly a year ago and references Snow Leopard, not Lion. The only absolutely correct recommendation I know of when it comes to using TRIM is "it depends". Garbage collection can NOT replace TRIM since the intended function of TRIM is to make GC more effective. But how well TRIM does or does not work depends not only on (1) how the OS uses it but also on (2) how the SSD's firmware responds to TRIM. In other words, "it depends ..." cc: @Hedge Jun 26 '12 at 17:15

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