Apple adds TRIM support for aftermarket SSDs in OS X 10.10.4
Some four years after adding TRIM support for first-party solid state drives to OS X, Apple incorporated the command for aftermarket drives as part of Tuesday's OS X 10.10.4 update.

Spotted by AppleInsider readers, the new capability allows users to enable TRIM functionality on third-party SSDs without resorting to unsanctioned workarounds or software. Prior to the change, Apple only supported TRIM on original Mac SSDs.
Enabling TRIM for non-OEM drives requires the
ArsTechnica reported on OS X TRIM functionality earlier on Tuesday.
Part of the ATA standard, TRIM helps optimize garbage data handling in SSDs by earmarking files no longer in use for permanent deletion. Unlike conventional spinning hard drives, SSDs perform erase operations before writing new files, meaning multiple erase/write operations could create a backlog of garbage bits that gradually slow the system down.
TRIM support for OEM drives first appeared in a beta for OS X 10.7 Lion in 2011.

Spotted by AppleInsider readers, the new capability allows users to enable TRIM functionality on third-party SSDs without resorting to unsanctioned workarounds or software. Prior to the change, Apple only supported TRIM on original Mac SSDs.
Enabling TRIM for non-OEM drives requires the
trimforce
command be entered into Terminal, specifically, sudo trimforce enable
. The system throws up a message warning users of potential incompatibility with certain SSDs before performing a reboot operation. ArsTechnica reported on OS X TRIM functionality earlier on Tuesday.
Part of the ATA standard, TRIM helps optimize garbage data handling in SSDs by earmarking files no longer in use for permanent deletion. Unlike conventional spinning hard drives, SSDs perform erase operations before writing new files, meaning multiple erase/write operations could create a backlog of garbage bits that gradually slow the system down.
TRIM support for OEM drives first appeared in a beta for OS X 10.7 Lion in 2011.
Comments
Yep, I can definitely see Apple bulking up the next revisions of their machines, adding complexity and thickness, in order to allow "user replaceable" parts. Totally happening.
About time! Maybe this is a sign that Apple's finally going to start allowing user-replaceable parts again (I can dream, can't I?)
I think a big reason for this change is external Thunderbolt drive arrays using SSDs, especially for the Mac Pro. They appear to the system the same as an internal SATA adapter card and drive.
Even Ubuntu will only run trim on Intel and Samsung SSDs by default. The trim implementations on many of the SSDs out there is poorly implemented it seems.
It's probably a reflection of how a vertically integrated hardware maker prioritized things. But yes, with aftermarket SSDs a popular upgrade option for older MacBooks, Minis, and iMacs, this is welcome news.
Ha. Just turned on TRIM before the update via a software patch. Upgraded my 500GB HDD to a Samsung Evo SSD.
I hope this is not your case case but according to a comment from Ars Technica (http://arstechnica.com/apple/2015/06/latest-os-x-update-allows-you-to-enable-trim-for-third-party-ssds/):
There are a number of extremely buggy SSD models out there (like almost all the Samsung 8* and various Crucial models) that will permanently delete the wrong data when issuing TRIM commands.
The bug is not dependent on queued TRIM, it happens even when using the non-queued version.
All the Samsung SSDs beginning with a "8" (840 and 850, both EVO and Pro) are known to have the data-destroying TRIM bug and TRIM is blacklisted on those drives on other platforms.
But maybe that warning is just valid for Linux (if you follow the link in the comment, that's all they talk about).
Wow, thanks for that, really. After treading looks like more of an enterprise problem due to different file systems. Shouldn't affect me, I don't think.
SAMSUNG SSD 830 Series:
Capacity: 256.06 GB (256,060,514,304 bytes)
Model: SAMSUNG SSD 830 Series
Revision: CXM03B1Q
Serial Number: S0XZNEAC600425
Native Command Queuing: Yes
Queue Depth: 32
Removable Media: No
Detachable Drive: No
BSD Name: disk0
Medium Type: Solid State
TRIM Support: Yes
Partition Map Type: GPT (GUID Partition Table)
S.M.A.R.T. status: Verified
Same here. Why fix something that is not broken? Have been using my crucial SSD for 18 months now without any noticable slowdown or otherwise inexplicable data loss.
It's not broken but it doesn't work. Garbage collection only works when the controller built into the SSD understands the file system. And I don't know of any that understand HFS. The TRIM command is sent from the OS which knows what blocks have been freed.
It's not broken but it doesn't work. Garbage collection only works when the controller built into the SSD understands the file system. And I don't know of any that understand HFS. The TRIM command is sent from the OS which knows what blocks have been freed.
Yep. Without TRIM the garbage collector will be diligently moving and compacting blocks that aren't even in use any more.
Got the warning, hit the "y" button. Told that it was successful and that the machine would reboot, hit the "y" button again. Waited ... after awhile I just rebooted myself.
Got the pop-up that Trim Enabler wasn't turned on, but upon opening it, it said that it wasn't necessary as the Apple Trim Enable was working. So, in short - it works on yesterday's release.
Ha. Just turned on TRIM before the update via a software patch. Upgraded my 500GB HDD to a Samsung Evo SSD.
I hope this is not your case case but according to a comment from Ars Technica (http://arstechnica.com/apple/2015/06/latest-os-x-update-allows-you-to-enable-trim-for-third-party-ssds/):
There are a number of extremely buggy SSD models out there (like almost all the Samsung 8* and various Crucial models) that will permanently delete the wrong data when issuing TRIM commands.
The bug is not dependent on queued TRIM, it happens even when using the non-queued version.
All the Samsung SSDs beginning with a "8" (840 and 850, both EVO and Pro) are known to have the data-destroying TRIM bug and TRIM is blacklisted on those drives on other platforms.
But maybe that warning is just valid for Linux (if you follow the link in the comment, that's all they talk about).
According to Xbitlabs this problem doesn't exist on Samsung 840 EVO SDD's as you mention. This is dated 3/10/2014
About time! Maybe this is a sign that Apple's finally going to start allowing user-replaceable parts again (I can dream, can't I?)
Why bother with Apple then? Just head over to Microcenter or Fry’s, buy a bunch of cheap parts off the shelf and assemble your own beige box and run Ubuntu. Who cares about design aesthetics, how things look, fit and finish, screws all over the place, stamped sheet metal cases, and multi-colored LEDs twinkling inside, weird decals, etc?
https://blog.algolia.com/when-solid-state-drives-are-not-that-solid/