People are often concerned with the performance of their SSD; is it running as fast as advertised. TRIM is an essential part of keeping your SSD performance up (see this article for details) and it has been very beneficial for Windows 7 users. However, for Mac users, TRIM is only available if you purchase an SSD straight from Apple when buying your Mac. The actual TRIM command is supported by OS X, so with minor kext modifications, it’s possible to enable TRIM on non-Apple SSDs as well. Terminal is needed for this and although it’s simply a matter of copying and pasting the commands, not all users are comfortable with using Terminal at all.

To make enabling TRIM more user friendly, Oskar Groth (also known as Cindori) developed an app called TRIM Enabler. The app has now reached version 2.0 and is finally fully compatible with OS X Lion. The 1.x version worked in Lion but it included an old kext from Snow Leopard that caused worse performance for some users. TRIM Enabler 2.0 patches the kext file for you and also repairs permissions, something you would have to do manually if using the Terminal method. TRIM Enabler also supports S.M.A.R.T. monitoring on some SSDs, allowing the user to see for example the lifetime reads and the amount of retired blocks.

As always, use such utilities at your own risk. Especially SandForce based SSDs have had problems with TRIM in OS X and it’s generally not recommended to enable TRIM with them--plus the built-in garbage collection in SF SSDs is fairly effective. I would recommend force-enabling TRIM in OS X only if you do something disk intensive where performance matters, and only if you have an SSD where idle garbage collection is proving insufficient; otherwise you most likely won’t notice the change in performance and you run the risk of unintended consequences. On the other hand, TRIM Enabler makes disabling TRIM as easy as enabling it, so giving TRIM a try shouldn't hurt anything. Moreover, you can always enable TRIM later on if you experience poor performance, and even disable it right after it has TRIM’ed the empty blocks in case TRIM causes problems with your SSD.  

TRIM Enabler 2.0 can be downloaded here!

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  • Impulses - Tuesday, January 24, 2012 - link

    Umm, all high end modern SSD have GC algorithms built in... Some are just more aggressive in how it works (Intel/SF vs Samsung/Crucial) but they all do GC.
  • jenniejohn - Monday, January 23, 2012 - link

    hmm this just awesome and informational.
  • ksherman - Sunday, January 22, 2012 - link

    "Moreover, you can always enable TRIM later on if you experience poor performance, and even disable it right after it has TRIM’ed the empty blocks in case TRIM causes problems with your SSD."

    How will we know the drive has been TRIM'd?
  • Kristian Vättö - Monday, January 23, 2012 - link

    You can erase free space in Disk Utility, that will clear the blocks if you have TRIM enabled.
  • star-affinity - Thursday, January 26, 2012 - link

    I'm under the impression the non-modular batteries Apple is using in their i-products and laptops is of a kind that be charged many more times (more cycles) then modular batteries. Should last a couple of years longer than other batteries.

    But I'm not sure about this. :)
  • star-affinity - Thursday, January 26, 2012 - link

    That, comment ended up in the wrong place.

    Too bad one can't edit or delete comments...
  • dagamer34 - Sunday, January 22, 2012 - link

    I had some issues when I enabled TRIM with the first version of TRIM enabler and it caused so many beach balls and stutters on my OCZ Vertex 3 that I turned it off and left it alone.
  • ckryan - Sunday, January 22, 2012 - link

    SF2281s don't really act like other drives during TRIM. Some of the SF2281 BSoD's are directly attributed to TRIM (and indeed, I've experienced this multiple times first-hand). SF228x drives are pretty relaxed about TRIM in general. Their garbage collection is good, but not nearly as aggressive as some Indilinx FW and some drives like the Corsair Performance 3 (The predecessor to the performance Pro).
  • PoopyPants - Wednesday, January 25, 2012 - link

    apple does things for very specific reasons, and i truly truly believe that the TRIM being disabled on non MAC ssd drives (via the OS) was done DELIBERATELY so that you would be FORCED to buy the 3x's over priced SSD with the Apple name on it.

    dont kid your self you fan boys, apple is smart and they know damn well that doing this increases their revenue because they can get more sales from people who want larger capacity.

    did they do it to ensure 100% hardware comatability, yes i believe they did as that has been the way builds their systems, always has been and always will be.
    the OS only works on certain hardware, the hardware only works on certain OS's. and when you try to backdoor that methodology you have to do some serious hacking to get it to work, or you buckle and buy the apple branded hardware.

    does apple care. pfpfpf hell no, they dont care one teeny tiny bit.

    i would almost bet that you very shortly will see Apple trying to have this software banned or removed as it circumvents some sort of bullshit patent apple thinks they have.


    i am a HAPPY macbook air owner, and MAC Mini. but i also own more PC's than MAC and i enjoy each and every system i have.
    but the Air and its soldered RAM and silly designed SSD was something i will never get over.
  • XianZhuXuande - Wednesday, June 27, 2012 - link

    By far the largest amount of Apple's money comes from sales to the general market. While they might pull some shenanigans during initial sale of a product (e.g. getting the upgraded RMBP model to upgrade the SSD) your theory of them excluding TRIM support from third-party SSDs specifically to encourage customers to purchase SSD upgrades directly through them strikes me as a conspiracy theory. Heck, you can't even find a SSD upgrade in their store unless you search for it properly, and even then, you're lucky to come up with more than an overpriced kit for 512 GBs in a Mac Pro.

    P.S. Your Air has a flat chip SSD because a 2.5" SSD would seriously interfere with their ability to make the machine so thin.

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