I added an OWC 240GB SSD to my 17" MBP a couple of years ago and installed Trim Enabler. Everything was dandy until yesterday when my computer somehow updated itself to Yosemite and I was faced with the "grey screen of death". I had an empty external drive already hooked up so I went ahead and installed Yosemite on it and copied up my latest Time Machine backup onto it. Starts up fine but I need to get my SSD back online. After researching I figured out that Trim Enabler and Yosemite were now bitter enemies. I am just trying to figure out now how to "disable" Trim Enabler from the SSD. Since I can't access the drive through Disc Utilities I'm not sure how to go about doing this. Do I have to take the drive out and hook it up as an external to disable Trim Enabler? Will that even work? I've since come to find out that Trim Enabler isn't really even necessary on the OWC Mercury that I have.

Help please!!!


  • 1
    Just to be clear, are you saying your SSD doesn't appear in Disk Utility? That may point to a slightly deeper issue other than the simple incompatibility between Yosemite and 3rd party TRIM enablers. As for the incompatibility, this page may help point you in the right direction - cindori.org/trim-enabler-and-yosemite - although if there is a problem with the SSD itself this will need to be addressed before tackling the TRIM issue. Mar 31, 2015 at 19:40
  • True. I may need to remove the drive and try to mount it as an external just to be sure it's not the drive that is failing.
    – Eric Wolfe
    Mar 31, 2015 at 21:58

1 Answer 1


See my answer here:

Since the release of 10.10.4, Apple now provides a new tool called trimforce, allowing users to activate TRIM also on unsupported disks. So now you can do:

sudo trimforce enable

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