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For the last two years I’ve had an OWC 480GB SSD drive in my mid-2013 MacBook Pro to replace the 256GB internal drive.

It's worked fine all this time until recently. Suddenly it wouldn’t boot up at all. Digging around using Disk Utility produced type-8 errors, and the only way to repair the drive was to wipe it. I tried that twice, but the same issue cropped up again.

Talking to OWC (macsales.com) led to them suggesting I do a clean install. However, you can’t do that with macOS 10.13.6. A message pops up saying that you can’t install it on a third party drive, or to be precise:

"macOS High Sierra cannot be installed because the third-party storage installed in your Mac is not compatible.”

On the phone to OWC again they suggested a different tack.


I tried that, and it didn’t work again, and I can’t try creating a bootable drive with an earlier version of the OS, because a message pops up saying “this version of OS is too old for this machine” (probably because the drive is formatted as AFPS). I’ve also tried re-formatting as an old Mac OS journaled format, and that didn’t work either, so my only conclusion is to avoid installing this at all.

It's quite disappointing, as the drive has worked fine until this point, but life is too short and I need a working computer.
 


It's quite disappointing, as the drive has worked fine until this point, but life is too short and I need a working computer.
I had a user with a 2015 Retina MacBook Pro that needed an SSD upgrade, and I went with an OWC Aura. They have a few different versions of their SSD though... one that only works with macOS 10.13, and one that works with older versions of OS X. Didn't realize this until I installed the Aura and couldn't install macOS 10.12 on it. Went back and forth with OWC until I got the "older" version and was able to put 10.12 on it and get my user back to work.

A few weeks later the user dropped his laptop and the Aura died(!) so I decided to cut my losses and tried an SSD from MCE. Was more expensive but appears to be an authentic Apple SSD that worked (and continues to work) perfectly.

I hear Transcend is now making Apple-compatible SSDs, so I might try them next time around. Or, maybe I'll tell my user to buy a laptop that uses industry standard SSDs instead of this silly and wholly unnecessary proprietary stuff. :)
 


I had a user with a 2015 Retina MacBook Pro that needed an SSD upgrade, and I went with an OWC Aura.
...
A few weeks later the user dropped his laptop and the Aura died(!) so I decided to cut my losses and tried an SSD from MCE. Was more expensive but appears to be an authentic Apple SSD that worked (and continues to work) perfectly.

I hear Transcend is now making Apple-compatible SSDs, so I might try them next time around. Or, maybe I'll tell my user to buy a laptop that uses industry standard SSDs instead of this silly and wholly unnecessary proprietary stuff.
I was a huge fan of OWC until the Aura debacle with my Late 2013 Mac Pro, which pretty much required sacrificing virgin chickens to upgrade to High Sierra. I finally installed the Bizon "Apple Genuine SSD 1TB Flash Storage Upgrade Kit for Mac Pro Late-2013." Aside from an interesting FileVault/4K monitor issue that has nothing to do with the SSD, it is working just fine.
 


I also have had OWC SSD drives die on me suddenly just after the warranty date. I have had better results so far with Crucial SSD's. OWC's response to the drive no longer working is that "the device is electronic and it happens."

SSD's are nice, but definitely keep backups of your data.
 


Reading this thread re: 'Trim', it just dawned on me that my recently-purchased 27" iMac Retina 5K has a 2TB Fusion drive. Should I (indeed, could I) be doing anything regarding Trim on this drive? If so, how? (The drive is formatted as Journaled HFS+.)
 


Ric Ford

MacInTouch
Reading this thread re: 'Trim', it just dawned on me that my recently-purchased 27" iMac Retina 5K has a 2TB Fusion drive. Should I (indeed, could I) be doing anything regarding Trim on this drive? If so, how?
That's a great question!

The design of Fusion drives raises serious questions about longevity of the SSD component, due to the very heavy usage and small SSD size. Here's a relevant discussion:
Howard Oakley said:
How long will the SSD (in my Fusion Drive) last?
...
If you have an SSD as your startup drive, or a Fusion Drive, you might like to make a rough estimate of the projected lifetime of your SSD: using DriveDx or a similar tool, take the size of your SSD in GB and multiply it by 5: that gives you the approximate quantity of data in TB which can be written to it before it is likely to start to fail. Compare that with the actual total data written in TB, given in S.M.A.R.T. indicator number 175, Host Write MiB.

The wear levelling count given in S.M.A.R.T. indicator 173 normally falls to around 90-95% in early use, but should then decline only very slowly. If it is approaching 50%, or even below, your SSD is wearing out.

Having come across one older iMac with a Fusion Drive which seems to be wearing out prematurely, I wonder if others may be similarly affected. If there was a bug in older versions of the wear levelling software, that could well be the case.
So, first of all, I'd suggest getting DriveDX (which I like) or something else that will report on the wear levels of your SSD.

Unfortunately, neither DriveDX nor Apple's Disk Utility seems to report Trim status, and I'm not sure how to check the status of Trim for your Apple Fusion drive SSD (although you could try Apple's About This Mac system report). I'd be curious to hear if anyone else has figured this out.
 


I'm not sure how to check the status of Trim for your Apple Fusion drive SSD (although you could try Apple's About This Mac system report). I'd be curious to hear if anyone else has figured this out.
Trim is enabled by default for all Apple shipped SSD's. You can check the Trim status of any SSD by going to System Information, and then choosing the interface (SATA or NMVe) and then clicking on the SSD device. You will see "Trim support" which should read Yes.
 


Ric Ford

MacInTouch
Trim is enabled by default for all Apple shipped SSD's. You can check the Trim status of any SSD by going to System Information, and then choosing the interface (SATA or NMVe) and then clicking on the SSD device. You will see "Trim support" which should read Yes.
Right. And the question is whether that works with a Fusion drive - I assume it does, then?

It gets a lot trickier with third-party/external SSDs (and Fusion drives). I'm having a lot of trouble identifying Trim status of these, despite having quite an array of disk utilities and other utilities.
 


Right. And the question is whether that works with a Fusion drive - I assume it does, then?
Yes. Fusion operates at the logical volume management level, several layers of abstraction above the device driver and controller level where Trim is operating, so it doesn't have any affect on Trim operation or reading the status.
It gets a lot trickier with third-party/external SSDs (and Fusion drives). I'm having a lot of trouble identifying Trim status of these, despite having quite an array of disk utilities and other utilities.
Third-party doesn't matter, as you can still read the Trim status the same way (and enable Trim via the trimforce command). The only tricky part is external USB enclosures (Thunderbolt ones are not a problem, if I recall correctly), and whether or not the bridge chipset passes through Trim status and/or SATA commands.
 


Ric Ford

MacInTouch
The only tricky part is external USB enclosures (Thunderbolt ones are not a problem, if I recall correctly), and whether or not the bridge chipset passes through Trim status and/or SATA commands.
Exactly. I have a Samsung T5, which is supposed to support Trim, connected to a MacBook Pro USB 3.0 port. There's no sign of Trim status in Apple's About this Mac profile (which does recognize Trim for the internal SATA SSD), but Disk Sensei says "The driver is installed and Trim is active."

By contrast, a Samsung 850EVO in an Oyen DIgital MiniPro enclosure in the other USB 3 port isn't even recognized as an SSD by Disk Sensei. DriveDX recognizes it correctly, but DriveDX doesn't show Trim status for anything, not even Apple's internal SSD.
 


Ric Ford

MacInTouch
Just checked pricing on the 2TB Samsung T5 (which I like), and it has fallen nicely:

Amazon Price History

Type

Price

When

Current

$583.00

Sep 20, 2018

Highest *

$799.99

Aug 18, 2017

Lowest *

$583.00

Sep 20, 2018

Average +

$671.37

-
* since Aug 15, 2017.
+ of the last 50 price changes
 
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The design of Fusion drives raises serious questions about longevity of the SSD component, due to the very heavy usage and small SSD size. Here's a relevant discussion....
If the spinning hard disk part of the Fusion drive fails, can you replace the spinning disk which has a SATA interface with a SATA SSD? Presumably, you could reconstitute the SSD and use the faster original SSD.
 


Exactly. I have a Samsung T5, which is supposed to support Trim, connected to a MacBook Pro USB 3.0 port. There's no sign of Trim status in Apple's About this Mac profile (which does recognize Trim for the internal SATA SSD), but Disk Sensei says "The driver is installed and Trim is active."
By contrast, a Samsung 850EVO in an Oyen DIgital MiniPro enclosure in the other USB 3 port isn't even recognized as an SSD by Disk Sensei. DriveDX recognizes it correctly, but DriveDX doesn't show Trim status for anything, not even Apple's internal SSD.
Maybe SoftRAID will report back whether there is Trim. SoftRAID seems to be able to set Trim for external hard disks.
 


Ric Ford

MacInTouch
If the spinning hard disk part of the Fusion drive fails, can you replace the spinning disk which has a SATA interface with a SATA SSD? Presumably, you could reconstitute the SSD and use the faster original SSD.
Actually, the problem is that the small Apple SSD may be more likely to fail, as it's so constantly in use, while the hard drive should chug along for years, as long as it's not defective.

And I'm not sure how fast the Apple Fusion drive SSD is - it would be interesting to get benchmarks on it. But, certainly, replacing the hard drive with an SSD should provide a lot better performance (if you could actually get to the drive to swap it...).
 



If the spinning hard disk part of the Fusion drive fails, can you replace the spinning disk which has a SATA interface with a SATA SSD? Presumably, you could reconstitute the SSD and use the faster original SSD.
I'm assuming you're asking about reconstituting the Fusion drive, irrespective of the data? Because Fusion drive doesn't provide any data redundancy - if you lose either portion of the Fusion drive, you lose all the data and must restore from backup.

So setting that aside, you could create a new Fusion drive using two SSD drives (a SATA SSD drive and the Apple built-in SSD). However, I don't believe that CoreStorage can differentiate between different classes of SSD performance (e.g. an NMVe PCIe SSD vs. an AHCI SATA SSD). It can only differentiate between SSDs and rotational storage. So with two SSDs, you wouldn't get any of the automatic data tiering that occurs in a normal Fusion drive. Instead, you'd basically just have spanned drives.
 


JDW

For me, thermal issues are a concern with the SanDisk for heavy loads, and I don’t know if it supports Trim. I don’t know of any downsides for the Samsung T5 except price. For non-intense usage, I assume the SanDisk would be fine, but if you're doing heavy-duty I/O, like booting your system off the device, I'd guess the Samsung T5 might be a better bet.
Although the current $583 Amazon price Ric mentioned for the Samsung T5 2TB is the lowest we've ever seen, the SanDisk 2TB Extreme Portable is now $499.99. It makes me wonder if those heavy-duty I/O considerations are worth the extra $83. My own intention for such an external SSD would be to connect the SSD to my mid-2015 MacBook Pro's USB 3.0 port for storing video footage that would be actively edited within FCPX 10.4.x.

Have any of you macOS High Sierra users formatted your external SSDs as APFS? I'm curious if the disk format affects Trim support. Or should we format all our SSDs APFS and not worry about Trim?
 


Ric Ford

MacInTouch
Although the current $583 Amazon price Ric mentioned for the Samsung T5 2TB is the lowest we've ever seen, the SanDisk 2TB Extreme Portable is now $499.99. It makes me wonder if those heavy-duty I/O considerations are worth the extra $83. My own intention for such an external SSD would be to connect the SSD to my mid-2015 MacBook Pro's USB 3.0 port for storing video footage that would be actively edited within FCPX 10.4.x.
If you're looking to pinch pennies and keep high performance, here's another approach (which may also have better thermal characteristics with its larger enclosure):
Total: $419.93
Performance: "over 800 MB/s"
(though you'd be limited by your 5Gbps USB 3.0 port)
 
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Ric Ford

MacInTouch
Have any of you macOS High Sierra users formatted your external SSDs as APFS? I'm curious if the disk format affects Trim support. Or should we format all our SSDs APFS and not worry about Trim?
I'm not sure about external drives, but Apple says that APFS supports Trim:
Apple said:
Apple File System Guide

Does Apple File System support TRIM operations?
Yes. TRIM operations are issued asynchronously from when files are deleted or free space is reclaimed, which ensures that these operations are performed only after metadata changes are persisted to stable storage.
More from Cindori:
Oskar Groth said:
Apple File System Slow Boot on High Sierra

...The latest issue with APFS comes in the form of introducing an extra 15 seconds of booting time when Trim is enabled. It is currently believed that the filesystem is performing a routine Trim-related cleanup process during this time, which is causing boot times to increase for users who want their SSD’s to benefit from Trim.

Enabling Trim with Trim Enabler or Disk Sensei still works fine in High Sierra and will not introduce any other issues. It is still required to enable Trim to get the feature on third-party SSD’s in High Sierra. Trim is an important feature for Solid State Drive performance and longevity. Some users who want to enable Trim on High Sierra may notice an increase in boot time for now. I have opened a discussion with Apple developers about fixing the boot time issue in APFS. I am convinced this is an unintentional bug in APFS from Apple’s side that should be fixed in an upcoming version of High Sierra.
Apple's trimforce command-line program provides a simple manual override of the Trim-hostile default setting but unfortunately lacks any "list" or "show" option to display current status (which seems really stupid). Also, the command is not documented by Apple in any official way that I can find, which also seems really stupid.

Cindori's Disk Sensei seems like the only good solution, currently.
 


Actually, the problem is that the small Apple SSD may be more likely to fail, as it's so constantly in use, while the hard drive should chug along for years, as long as it's not defective.
And I'm not sure how fast the Apple Fusion drive SSD is - it would be interesting to get benchmarks on it. But, certainly, replacing the hard drive with an SSD should provide a lot better performance (if you could actually get to the drive to swap it...).
My Fusion drive has a 128GB SSD plus a 2TB spinning drive running at 7200 RPM. Another office computer has the little SSD (28GB?) and a 1TB spinning disk, and it is noticeably slower than mine. My Fusion drive is AFPS encrypted, and I did nothing but install Mojave GM. If I use Blackmagic Speed Test, what value do you want?
 


Ric Ford

MacInTouch
My Fusion drive has a 128GB SSD plus a 2TB spinning drive running at 7200 RPM. Another office computer has the little SSD (28GB?) and a 1TB spinning disk, and it is noticeably slower than mine. My Fusion drive is AFPS encrypted, and I did nothing but install Mojave GM. If I use Blackmagic Speed Test, what value do you want?
I was hoping someone might have split up their Fusion drive and benchmarked the SSD separately (and you may not feel like doing that). What I do with Blackmagic Disk Speed Test is click the gear icon, choose 5MB, choose the target drive I want and then click Start, then click Stop when it seems to have (somewhat) solid data (usually in the middle of a subsequent Read test), then save the snapshot.

That's actually all kind of a PITA, and AJA System Test Lite is probably a better bet.
 



Exactly. I have a Samsung T5, which is supposed to support Trim, connected to a MacBook Pro USB 3.0 port. There's no sign of Trim status in Apple's About this Mac profile (which does recognize Trim for the internal SATA SSD), but Disk Sensei says "The driver is installed and Trim is active."
The T5 can support the concept of TRIM, but TRIM itself, probably not. USB doesn't support SATA. There is a UAS/UASP (USB Attached SCSI / USB Attached SCSI Protocol), but SCSI is not SATA. TRIM is a SATA command. UNMAP is a SCSI command that effectively does the same thing, but in a different protocol.

The "About this Mac profile" report's entry for a drive contains properties of both the drive and of the OS/file system. For example, ' BSD name' presents as a property of a disk in that report, but that isn't a property of the disk itself - that is the OS device name for the disk. Similarly with the 'trim' status there, it is primarily not a property of the disk. It is a property of the TRIM status that the file system has set about the disk. It doesn't originate from the disk.

trimforce is a command for the OS/file system to use the Trim attributes of the drive. All the modern SSDs have the property - it is whether macOS chooses to use it or not (deem it trustworthy).

Technically, though, for USB it isn't TRIM that the file system has to use, it is UnMAP. If the file system doesn't make any UnMAP calls, then it wouldn't be used.
https://www.tomshardware.com/reviews/samsung-t5-portable-ssd,5163-3.html
... Previous versions of the Samsung Portable SSD did not support TRIM. The new T5 products accept the command from the host through the UASP protocol. The feature doesn’t work with the native exFAT file system that provides compatibility with Android and other devices. You will need to format the Portable SSD T5 with the NTFS file system for TRIM to work. Increased compatibility will be more important for some users, but if you only use Windows, we suggest using NTFS to gain access to the TRIM feature. ...
That happens because NTFS can send UnMAP commands to SCSI devices. Microsoft's exFAT doesn't. If Apple's file system doesn't send the commands, then it won't 'work'.
By contrast, a Samsung 850 EVO in an Oyen DIgital MiniPro enclosure in the other USB 3 port isn't even recognized as an SSD by Disk Sensei. DriveDX recognizes it correctly, but DriveDX doesn't show Trim status for anything, not even Apple's internal SSD.
Two of the issues with USB/SCSI and SATA SSDs are whether the metadata about the drive is all translated/accessible (e.g., S.M.A.R.T data) and all of the commands are translated. The USB UnMAP has to be converted to a Trim command and passed on. That could be an issue with different controller implementations.
 


Yes. Fusion operates at the logical volume management level, several layers of abstraction above the device driver and controller level where Trim is operating, so it doesn't have any affect on Trim operation or reading the status.
Core Storage (Fusion) is above and below the device driver abstraction level, not strictly above. It presents a virtual device which drivers can interact with. You can do block-level commands to a Fusion drive (which get translated to another set of block level commands).

Normally, the file system is using Trim. The file system is above block level. Who/what invokes the Trim (or UnMAP) command is important to whether it is being utilized or not. The 'other' end (the device) isn't as big of an issue.

For Fusion drives, there is a block remapping being utilized. That remapper can manage the block (which could easily include Trim). It is effectively a simple, single-purpose file system in a general sense (not GUI/user interaction sense). So, while the file system may not be using Trim on a Fusion drive (because the bulk of the data is on a hard drive), the block remapping and caching system can easily use Trim (or UnMAP if implemented) to 'clean up' the cache blocks as they are dynamically changed.

It would be more then kind of goofy if it did not, since dynamic caching (as automatic storage tiering) involves a significant number of writes - Fusion even more so, since it targets the SSD as a 'write first' device, so all changed blocks nominally go there first.

APFS stuffs some of the features of Core Storage into the "file system". APFS is doing block management, so it just as capable of using it with the caching (auto storage tiering) option even if 'TRIM' isn't being applied to all block under management of a whole file system Volume. When the blocks is moved from one storage device to another, TRIM could be used when removed from the SSD.
Third-party doesn't matter, as you can still read the Trim status the same way (and enable Trim via the trimforce command). The only tricky part is external USB enclosures (Thunderbolt ones are not a problem, if I recall correctly), and whether or not the bridge chipset passes through Trim status and/or SATA commands.
Again, trimforce is more so about the status of the file system, not the device. The devices don't change status. They have a Trim command as part of their basic SATA command implementation. It is really the status of whether the file system considers it a trustworthy implementation or not.

USB doesn't pass SATA commands.

Thunderbolt can also create an issue if the disk controller on the other side only presents back a single virtual drive - for example, a bootable RAID controller that presents as being just one singular drive.

Thunderbolt is a 'clean' path, directly talking to the individual SATA devices (e.g., a one-on-one connection to a SATA controller).
 



Ric Ford

MacInTouch
... Similarly with the 'trim' status there, it is primarily not a property of the disk. It is a property of the TRIM status that the file system has set about the disk. It doesn't originate from the disk.

trimforce is a command for the OS/file system to use the Trim attributes of the drive. All the modern SSDs have the property - it is whether macOS chooses to use it or not (deem it trustworthy).

Technically, though, for USB it isn't TRIM that the file system has to use, it is UnMAP. If the file system doesn't make any UnMAP calls, then it wouldn't be used....
A few related notes:
  • Reading Cindori's documentation, it appears that Apple's trimforce command actually modifies an Apple driver file. (Again, it's shameful that Apple has not documented this in any way.)
  • Cindori's Disk Sensei apparently uses a driver of its own to activate Trim for third-party drives.
  • Disk Sensei shows the status of Trim for individual devices - and it shows Trim enabled for a Samsung T5 on my system but not enabled for other USB 3 devices.
  • I'm running the SAT SMART driver, which could be a factor.
  • I haven't tested to find out if Trim is actually functioning on the T5... and I don't know how to do a definitive test of that.
 



The design of Fusion drives raises serious questions about longevity of the SSD component, due to the very heavy usage and small SSD size. Here's a relevant discussion...
Howard Oakley said:
How long will the SSD (in my Fusion Drive) last?
... take the size of your SSD in GB and multiply it by 5: that gives you the approximate quantity of data in TB which can be written to it before it is likely to start to fail....
There are two sizes of an SSD. One is user-accessible. The other is the raw size. Some amount of each SSD is allocated to administration/overhead/over-provisioning. A sizable over-provision area allows the SSD to do better wear-leveling. That is just over-provisioning by the hardware. If you partition the SSD and leave a small partition fallow (unused by any file system), you can pragmatically increase the over-provision area.

If Apple's Fusion SSD presents as 120GB, it is likely that at least another 8GB has been assigned to over-provision duties. Same for Apple's 32GB SSDs. At the prices Apple charges, that could be a 64GB raw SSD with a very high over-provision percentage.

The latest generation TLC SSD overall wear metrics have gotten much better than SSDs 3-4 years ago, not because their cells are less 'fragile' but in part because there are more 'extra' (over-provision) cells to allocate usage over (and there are fancier wear-leveling algorithms and dynamic switches between SLC, MLC, TLC usage).

S.M.A.R.T. attribute 173 is for the worst erase count on any block. If the controller can find some read-only data and stuff that into that block, that is only an indirect indicator. If that goes down really fast, that is probably more an indicator that the controller's guess about what is primarily static (read only) data is way off.

Apple also puts some 'cheats' into Fusion. The area to restore RAM from drive, so 'wake from sleep' is fast, is likely highly prioritized onto the SSD (a reason why Apple doesn't recommend Fusion for Macs with RAM larger than the Fusion SSD target). The second prioritization is around the OS kernel (again booting and waking like an SSD-only device is a primary objective).

A far higher level of wake/sleep cycles from a very large RAM Mac could drive the wear level indicators quite high (as in the article ). The targeted 'slow'-changing OS can work with a smaller SSD. Hybrid drives (SSHD) have even much smaller 'SSD' components (in the 8GB range) - for example, the FireCuda 2TB. The algorithm for what to cache makes a difference. (With a smaller SSD, one can get more conservative about what to hold on the SSD storage tier and may juggle slightly more stuff in RAM for the read cache.)
Unfortunately, neither DriveDX nor Apple's Disk Utility seems to report Trim status, and I'm not sure how to check the status of Trim for your Apple Fusion drive SSD (although you could try Apple's About This Mac system report). I'd be curious to hear if anyone else has figured this out.
IHMO, there should be an "APFS Utility" program, as opposed to trying to stuff this into Disk Utility. First, it isn't an attribute of the drive. Second, the volume management is related to the drives but has its own complexities when you start to cobble together multiple disks with multiple volumes (and snapshots) layered on top. Apple could add (has added) that as an integrated viewer merged into Disk Utility, but I suspect they will have problems because folks will use the original Disk Utility "mental model' when trying to interpret those views.
 


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