As you may know there are opposing arguments on enabling TRIM on Mac OS X systems.
Some people claim that, since it’s blacklisted in Linux systems, TRIM should never be enabled in Mac OS X systems for Samsung 8xx SSDs. I have seen other people claiming Samsung suggests not enabling it, while other people like Scott here, claims that Samsung blamed him for loss of device as he didn't enable TRIM.
Anyway, I have read Temptin's comment in this post and decided to enable TRIM on my Mac as well (I have Samsung 850 PRO). S/he argues with evidence that Samsung 850 PRO have implemented sequential TRIM, and Mac OS X 10.11 (El Capitan) also uses sequential TRIM.

But, after enabling TRIM I felt a bit uncomfortable from all I read.

Since all I have read was a bit dated, my question would be is there any update on this debate? Is there any recent evidence that may suggest disabling TRIM will be more beneficial or enabling TRIM will have dire consequences?

  • The "blacklisting" simply means that Linux will send non-queued TRIM commands for the devices on that "blacklist". So I think "blacklist" is a bit of misnomer. A more accurate name for this "blacklist" is: "DevicesForWhichWeNeedtoSendNonQueuedTrimCommands". :). en.wikipedia.org/wiki/Trim_(computing)
    – Gino
    Jul 20, 2017 at 15:02

4 Answers 4


one of my businesses does a lot of customized Mac work, and we upgrade 50-60 Macs per week.

Primarily SSD and SSHD drives, ram, stripping Mac OSs down for best performance, etc.

We've NEVER ONCE had any issue with any Samsung SSD with TRIM. not a single time. nada...

The gained performance is noticeable as well.. pretty powerful.

I wouldn't give it a second thought.... we install it on every SSD.

  • Briefly, I was just made aware of this TRIM after constructing a clone-only backup system which hourly clones the internal SSD's of a iMac 5K 1TByte OEM SSD to an external SamSung EVO 850 2TByte, which is in a LaCie Ruggedized Thunderbolt Chassis (rotational replaced) off the Thunderbolt port. Enabled trimforce and booted off this external SSD, deleting 700GByte of cruft, and filling it back up - all is fine running off this trim force enabled SamSung EVO 850 2TB SSD. Jul 17, 2016 at 12:21
  • In another room, my macbook, which boots off a thunderbolt LaCie Ruggedized SSD, upgraded the rotational to a 2TByte Samsung 850 EVO SSD Pro, which is actually daisy chained off a thunderbolt Belkin hub that leads back to the macbook retina. This mac has been running El Capitan with trim force enabled for a week now, no issues, yet. Jul 17, 2016 at 12:25
  • The above 2 Macs, the iMac 5K (Yosemite with trim force enabled) and the macbook retina (el capitan with trim force enabled), also have two other 1TByte partitions whose sole purpose is to receive hourly identical clones via the remote Carbon Copy Cloner rsync invocation over ssh, essentially created networked trim force enabled clones of the production iMac and macbook. These clones are all bootable, but unfortunately, the fullest one is for a Mavericks boot, so I won't be trying trim force enable there, but the other two hourly clones, which have been being cloned for months, now, both boot Jul 17, 2016 at 12:28
  • In summary, I have 3 SamSung 2TByte SSD's, an 850 and 850Pro, and 2 are divided into 1TByte partitions, the 3rd having a single 2TByte partition, but these 5 partitions are the recipients of hourly CCC clones, and have for some time, and the clones have filled up, been cleaned out, filled, etc. I finally turned on trim force, and did quite a bit of moving around, more to follow, and all boot and operate as expected. Jul 17, 2016 at 12:31
  • 1
    So, in support of frank's assessment, I'm not giving my trim force enabled samsung 850 SSD clone force a second thought - they are and have been working great. Jul 17, 2016 at 12:31

Linux uses queued trim, having problem with some SSDes. Both Windows and OS X use sequential(non-queued) trim, so should be safe to enable trim in OS X.


Mine has been enabled for 4 months now (850 EVO 1T) and I haven't had any issue.

More importantly, speed has remained consistently fast. Didn't get any slower at all.

So it seems to work AND to be reliable.

I would leave it enabled, if I were you.


Installed 250GB Samsung EVO 850 in iMac 27 2010 mid-model as fusion drive with original 2TB HD. No TRIM enabled. Restored 1TB+ to the fusion drive.

Tested with BlackMagic, 260MB/s read (which is max for SATA-I interface), 30MB/s write!!!

Enabled TRIM, retested with BlackMagic and now getting 260MB/s read and write.

So I think trim is important when using EVO SSD's in Fusion drives.

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