TRIM support in OSX

Many Mac users where extremely disappointed last year, when it was discovered that OSX 10.10 or Yosemite had apparently abandoned TRIM support for all non-Apple SSD’s, thus severely limiting the upgradability of older Macs.

What this basically meant was that if you purchased an Apple Computer that came with an SSD, then TRIM was automatically enabled.  In fact, you’s be hard pressed these days to find a Mac that doesn’t come with an SSD as default, or at least offer one as an upgrade at time of purchase.

But if you had an older Mac that came with a mechanical or ‘spinning’ Hard Drive and wished to upgrade to an SSD, there was simply no way to enable TRIM. It was permanently disabled.

Before OSX 10.10 there was a utility called ‘Trim Enabler‘, which once installed would activate Mac TRIM support on all non-Apple SSD’s. This utility while being a little clunky, did the job and seemed to work well. But all this came to an end once Yosemite shipped in the fall of 2014.

So what’s the big deal about TRIM?

The Trim command is designed to enable the operating system to notify the SSD which pages no longer contain valid data due to erases either by the user or operating system itself. During a delete operation, the OS will mark the sectors as free for new data and send a Trim command to the SSD to mark them as not containing valid data. After that the SSD knows not to preserve the contents of the block when writing a page, resulting in less write amplification with fewer writes to the flash, higher write speed, and increased drive life.” – Wikipedia

Simply put, TRIM not only extends the life of your SSD but it also keeps it efficiently running at top performance.

Luckily all is not lost if you are running OSX 10.10.4 or above.  Apple has, without fanfare, secretly enabled TRIM support in Yosemite and going forward TRIM support will also be built in by default in the upcoming 10.11 or El Capitan.

So how do you enable TRIM support in 10.10.4 or above?  It’s very simple.

TRIM needs to be enabled from the OS X TERMINAL.

To get to the terminal on your Mac, you can launch Spotlight and just start typing TERMINAL and it will appear, click to launch.


Open your applications folder and navigate to the UTILITIES folder, TERMINAL will be located there.

Once TERMINAL is open, type or cut and paste the command below and hit enter.

sudo trimforce enable

You’ll be prompted to enter your password, do so and hit enter.

That's it, TRIM is now enabled on your Mac!

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