How to enable TRIM on a mac with an aftermarket SSD

Enabling the TRIM command will allow Mac OS X to perform garbage collection on the Solid State Disk (SSD) to optimize write speeds. SSDs are very fast out of the box, but without TRIM, write speeds can gradually decrease over time as the disk becomes slower at overwriting previously used blocks. If your mac came with an SSD from the factory (like those awesome new MacBook Airs), then TRIM is already enabled and you’re good to go. But if you upgraded to an SSD on your own, and you’re experiencing slowdowns you may want to read on.

For a full background on TRIM, and what it does consult this article.

Thanks to Oskar Groth’s Trim Enabler app, it has become incredibly easy and safe to get TRIM working with just about any SSD. No need for fussing with command line on the Terminal. Just download the app, flip the switch, and you’re good to go. But before you check it out, here are three things you need to know.

  1. Does your SSD support TRIM? Check the manufacturer’s website to find the specifications of your specific model, most of the new SSDs on the market today support TRIM.
  2. You need a fairly modern version of Mac OS X. TRIM was added to Snow Leopard in version 10.6.8, so anything newer than that should work.
  3. This isn’t officially supported by Apple, so you’re doing it at your own risk. We super strongly recommend that you make a backup of your data before enabling TRIM should something go wrong. You can make a bootable backup, or at the very least a Time Machine backup. You have been warned.

Trim Enabler also gives you a handy S.M.A.R.T status readout about your SSD.

In case you have to ask: TRIM is only useful for SSDs, if you have a regular hard drive this won’t improve its’ performance.