OS X El Capitan Enables TRIM Support on Third-Party SSDs


Users owning older Mac computers have been able to extend the life of their devices using third-party solid-state drives (SSDs). However, there was an issue some of them faced after the neat upgrade: The lack of support for TRIM on these devices caused a drop in writing speeds after the drive began to fill up. The good news: OS X El Capitan allows users to enable support for TRIM, as noticed by MacRumors forum users.

TRIM is a system-level command that essentially allows the system to check which areas of the drive are considered unused, so they can be erased and rewritten.

There are tools available to enable TRIM for third-party devices, but since it is only supported on Apple drives, under Yosemite this wasn’t possible, due to Apple’s use of kext signing, a security measure the company uses.

Given the “rootless” option available now with OS X El Capitan, some knowledgeable users have started playing around with utilities such as TRIM Enabler, and Macrumors forum readers discovered that it is possible to enable support for TRIM on third-party drives, as soon as “rootless” has been disabled.

Apple is aware of this, so when enabling TRIM support, you get a warning message, but I think it is worth taking the risk and, as such, saving millions of neurones from death.

Image credit: Macrumors

Technology enthusiast, rocker, biker and writer of iPhoneinCanada.ca. Follow me on Twitter or contact me via email: istvan@iphoneincanada.ca

  • sukisszoze

    I put in a SSD on my 2010 iMac..and it’s running like new.

  • Carlos

    I have a 2010 iMac and was thinking about doing the same. Did you have it professionally installed?

  • sukisszoze

    Yes, Sandisk Extreme Pro 960G installed by a local computer store for $100 in labour as I wasn’t going to try pull the screen apart to do this. They install the SSD around some free space with a kit so I can keep my HD in the computer. It was easy for me to copy over the files using SuperDuper.

  • Carlos

    Interesting. When you say free space do you mean there is enough in there without removing anything? My local store said I had two options; I could either replace the hard drive with a SSD or add one by removing the optical drive.

  • sukisszoze

    You can keep your HD and optical drive by using this kit: OWC 27″ Imac 2010 SATA 3GB/s DIY Kit w/Power “Y” Cable (as per my invoice), it’s about $30. Afterwards, I use a fan control app to keep the fan speed down because the Mac thinks it’s overheating.

  • Carlos

    Thanks for the info!