About Trim in Yosemite

In OS X 10.10 (Yosemite), Apple has introduced a new security requirement called kext signing. Kext signing works by using signatures to verify drive integrity. If a have been modified, Yosemite will no longer load the driver.

Trim Enabler support

Trim Enabler 3.3 and older worked by modifying a system driver. But thanks to Apple opening up access to their drivers and providing us with a kext certificate, you can now enable Trim safely using Trim Enabler 3.4 or Disk Sensei 1.2.

Important issues

If you try to use an older version of Trim Enabler, you could end up with the “gray stop sign” screen when trying to boot. To avoid this situation, use Trim Enabler 3.4 or later, or the new Disk Sensei.

