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Samsung T5 External SSD - Is TRIM supported on Mac OS Sierra?
- Thread starter rsg1010
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Chances are, TRIM isn't supported.
BUT... don't worry about it.
TRIM will make next-to-no difference at all. It's one of those issues that is "lots of smoke but no fire".
I've been booting and running a 2012 Mac Mini for almost 6 years using an SSD in a USB3/SATA dock. The lack of TRIM has never been an issue ... NEVER.
Having said that, I keep plenty of free space on the SSD, so the OS has "room to breathe".
BUT... don't worry about it.
TRIM will make next-to-no difference at all. It's one of those issues that is "lots of smoke but no fire".
I've been booting and running a 2012 Mac Mini for almost 6 years using an SSD in a USB3/SATA dock. The lack of TRIM has never been an issue ... NEVER.
Having said that, I keep plenty of free space on the SSD, so the OS has "room to breathe".
TRIM is supported in HS but you can't send SATA commands like trim over USB as far as I know. its also not really needed anymore as modern SSDs have garbage collection built in so you can have that thing packed all the way full without issue. thats what I've done for years now without a single issue.
Irresponsible and oft-repeated misinformation based entirely on one user's own circumstantial experience.
When that problem-free SSD he keeps basing this declaration of TRIM's irrelevance on does eventually die it may have been twice as fast as it would have in a TRIM-enabled machine.
No, TRIM does not work over USB in macOS and yes, TRIM absolutely does make a difference in performance and significantly reduces write amplification.
The lifetime of an SSD is calculated in write cycles.
No. TRIM DOES NOT matter that much any more.
It's Sushi's "advice" that is misinformation.
I stand by this post.
An open request to anyone reading this that is currently booting and running an iMac or Mini via USB:
Has the lack of TRIM mattered much for you?
If so, have you been able to document the information?
I say to Sushi:
Put up, or shut up.
Produce documented info if you have it.
For someone with an older Mac (2012-2015), who has only a platter-based hard drive inside, and who wants to "squeeze more years of use" from it, adding an external USB3 SSD is a cost-effective solution. No breaking open the machine, no risk of breaking something inside.
It will greatly speed up the computer, and so long as the user leaves a good amount of free space on the SSD, it will probably continue to perform well long enough to "outlive" the computer itself.
It's Sushi's "advice" that is misinformation.
I stand by this post.
An open request to anyone reading this that is currently booting and running an iMac or Mini via USB:
Has the lack of TRIM mattered much for you?
If so, have you been able to document the information?
I say to Sushi:
Put up, or shut up.
Produce documented info if you have it.
For someone with an older Mac (2012-2015), who has only a platter-based hard drive inside, and who wants to "squeeze more years of use" from it, adding an external USB3 SSD is a cost-effective solution. No breaking open the machine, no risk of breaking something inside.
It will greatly speed up the computer, and so long as the user leaves a good amount of free space on the SSD, it will probably continue to perform well long enough to "outlive" the computer itself.
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Here was my reply to your demand almost a year ago. If you like, I can find other posts with more examples.
I understand you have not had any issues running without TRIM, but some users do.
I'm curious if anyone can shed some light on this:
1) Why/How does Windows support trim on this particular SSD external drive (Samsung T5) over usb compared to Mac OS? Is the limitation of TRIM predominately based on the OS rather then the physical connection of the drive being used?
2) What if I am using Parallels (Windows 10) in conjunction with With Mac OS Sierra via USB-C. Would TRIM work when Parallels is running? Or how about using a windows 10 desktop and also a 2016 Mabook Pro. IF I am going back and forth between different computers, does trim work when connected to the windows 10 desktop?
Thanks for the info everyone. Much appreciated!
1) Why/How does Windows support trim on this particular SSD external drive (Samsung T5) over usb compared to Mac OS? Is the limitation of TRIM predominately based on the OS rather then the physical connection of the drive being used?
2) What if I am using Parallels (Windows 10) in conjunction with With Mac OS Sierra via USB-C. Would TRIM work when Parallels is running? Or how about using a windows 10 desktop and also a 2016 Mabook Pro. IF I am going back and forth between different computers, does trim work when connected to the windows 10 desktop?
Thanks for the info everyone. Much appreciated!
Thanks for the info. Quick question. Is that Powershell Command run every time the SSD Drive is connected via USB to the computer or once only? Does it subsequently send the correct commands everytime when the SSD Drive is attached to that computer?
Thanks
Garbage collection is an additional feature, while TRIM is a mandatory feature, especially for OS and applications disks (virtual memory).
Relying on garbage collection instead of TRIM is viable to some degree but not ideal. I bought a Mac Mini in 2012. I didn't want to go through the trouble of switching the internal drive to an SSD so I bought a 2.5" SSD and put it in an external enclosure and used that as my boot drive. It worked well for about 2 years but then I started experiencing horrible slowdowns if I wrote more than ~1GB to the drive over the course of a few minutes. Clearly I was exceeding the ability of the drive to free up empty blocks. It didn't happen often enough but the slowdowns were bad enough that I had to do something about it. (The system would hang for several seconds if it tried to write ANYTHING to the drive past ~1GB and it would stay like that for 15-30 minutes.) I bit the bullet and installed the drive internally, enabled TRIM, and that eliminated the slowdowns.
Hi all, Im new here.
Mac TRIM over USB possible new info. So I got an Samsung Evo 860 into a USB 3.1 Gen2 enclosure. Driver formatted to APFS
- Using BlackMagic Speed
- Used the 5GB test, initial bursts speed were even higher than below (probably drive cache)
- Result: Write: around 480MB/s Read around 500MB/s
- Turned TRIM on via terminal (even though TRIM is not suppose to be supported over USB)
- Same Test = Write: around 520MB/s Read around 1600 -1700 MB/s
- Then turned TRIM off again
- Speeds went back to 480MB/s Read around 500MB/s
- Then turned TRIM ON again
- Speeds went back up to 520/1600+MB/s
1700MB/second is 13.6 gigabits/second, and well above the maximum throughput for USB 3.1 Gen 2. This "benchmark" is obviously caching data and is not accurate.
Trim is not supported on USB in macOS.
Yes but, how do you explain that the cache on this is far lower (1GB) and the test is set to 5GB? Thats why I set the test at 5GB to avoid any cache 'misreadings'. The 1600-1700/MB/sec was sustained, it lasted the whole 5GB write test cycle and I did the test several times with the same result. If this was purely cache, would it not simply burst into 1600MB/sec for about 1/4 of a second then hover to it's advertised 550MB/sec thereon.
What do you make of this?
The only thing that can be made of it is that the benchmark application is not working properly. It's simply impossible to get 13Gb/sec out of an interface that's only rated to a maximum theoretical 10Gb/sec.
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As has been pointed out, something is wrong with this benchmark software if you're getting 1700 MB/s over USB, since that's impossible.
But also, it's not clear if your drive is new or not. TRIM will only have an effect on drives that have been used enough to have all their [non-overprovisioned] blocks filled with data. TRIM will have no effect on a new drive that hasn't been written to very much.
[doublepost=1551374650][/doublepost]Another data point re: TRIM and garbage collection.
I have a 3rd party SATA drive mounted in my 2012 Mac Mini. When I installed it, I enabled TRIM via "TRIM Enabler" and it worked fine.
A couple months ago, I felt like my computer was slower than it should be when writing to the drive. Turns out that since I installed the drive, TRIM Enabler had stopped working. Blackmagic was reporting write speeds to the drive of around 50 to 120 MB/s.
I re-enabled TRIM via Apple's newish "trimforce" utility and write speeds are back over 400 MB/s for the drive.
So to anybody thinking that garbage collection is somehow a replacement for TRIM, or eliminates the usefulness of TRIM, that is absolutely not true.
Meanwhile, I did some research and apparently there are some external USB drive enclosures that support the UASP protocol and translate the SCSI UNMAP command to the SATA TRIM command. So now it is possible to have TRIM over USB although I don't know if MacOS sends these UNMAP commands to UASP drives. Maybe somebody else knows the answer to that.
Here is an older post of mine that discusses this.
You can run the UNMAP command from Windows, but macOS does not support it.
Interesting, thanks. It sounds like the Windows command is just to force-TRIM a drive's empty space. Just because MacOS doesn't have a similar force-TRIM/force-UNMAP command doesn't mean it doesn't send UNMAP commands to UASP drives as files are deleted.
Somebody could test MacOS's UNMAP support by taking a blank, properly-TRIMMED drive, benchmarking it, then filling it up completely with data, then deleting some of that data, and then benchmarking it again. If the benchmark results are the same then it would be a clue that UNMAP commands are being issued.
I would do this myself but I don't have an appropriate drive or enclosure for such a test.
Ah yes, since USB3.1Gen2 can't exceed 10Gbps Im very curious why 1700MB read happens only with TRIM enabled and drops to about 480MB/sec with TRIM disabled. It' certainly weird, especially over USB mac.
PS: The Samsung 1TB Evo 860 Im testing on is brand new. My BMD benchmark tool is version 3.2
Well the other weird thing is that TRIM should have literally no effect on read performance, it's only an optimization for writing data to an SSD.
So TRIM being enabled or disabled is really irrelevant here. Also, I don't even know what it means for TRIM to be enabled or disabled in this case, because TRIM is enabled/disabled on a per-drive basis. How are you enabling TRIM on a USB drive? There isn't a feature in MacOS to do this.
[doublepost=1551382556][/doublepost]
Not only will TRIM have literally no effect on read performance in any situation, TRIM will have no effect on write performance for a brand-new drive, until it has been completely filled with data.
Something has gone wrong with your benchmark software. Whatever it is, it isn't related to TRIM.
Oh okay, right, yes, that will only affect SATA drives. There is no way to enable TRIM for USB drives, as has been discussed, because there is no way to issue SATA commands over USB. There is a way to issue SCSI commands, via UASP, hence the discussion of UNMAP being translated to TRIM. But I doubt that a command called "trimforce" would enable the SCSI UNMAP command.
But this is all a moot issue with regard to your benchmark results, for the reasons I explained earlier.
Oh well, we will never know then, maybe BMD Speed-test was faulty, will never know now, I returned the USB enclosure and and now have a bare SSD -> now looking to buy Thunderbolt enclosure.
