External SSD Strangely Slow Read Speeds - Advice?

[DeepSix]

I would replace it and put in a 4TB Samsung Pro.

 

[Church13]

I would replace it and put in a 4TB Samsung Pro.

Bro, I literally just posted that I bought a 1TB SN850X and it's performing nominally / as I'd expect, therefore resolving the issue I opened the thread for. But sure, yeah. I'll get right on buying a drive at a price I don't want to spend for capacity I don't need for my use. Another Samsung to boot too, which may or not have the same issues I was experiencing with a *different* Samsung drive I was already using.

 

[StoneJack]

Sometimes the simple answer is the best answer. I think in general you'd get more traction with your input if you did more than just post it as a lowercase one-liner though, lol.



I ended up picking up an SN850X, found a good sale and bought it for $15 more than a 1TB SN770, so definitely worth it in that regard. And of course, as soon as I formatted it and gave 'er a test:

View attachment 2486591

Darned impressive numbers, maxing out the USB4 link for sure. Apple and macOS really just like the WD nvme controllers. Which brings me to what I've discovered is incompatible about the Samsung (and potentially the Hynix drive as well, though as we've discussed it's not confirmed whether I truly tested it with the latest firmware or not).



Yeah, no luck with the firmware, but what I have figured out is why it hates the Samsung drive especially. It all has to do with power state management...which macOS is not doing a great job with. It appears to be going into a low power state when not in use. Naturally, the writes "wake" the drive up, but then it returns to the low power state and the reads absolutely suffer.

AmorphousDiskMark loads the drive differently, and keeps it in the high power operating state. Blackmagic and regular use just don't put the drive in a high enough power / activity state for reads to perform where they should.

glad you resolved the issue. I had similar issues with Samsung drives before in Hackintosh desktops which I assembled and the culprit was Samsung. So I figured out you had similar incompatibility and also I did a bit of research. Samsung was reported to have such problems in 2021 for sure with Macs. My answer to you was a bit of intuition as in my case after changing to Black edition WD all my Mac boot problems were forgotten and I got best speeds and operations for last 3 three on my huge Intel K10900 desktop Hackintosh. So stay away from any incarnation of Samsung drives

 

[bzgnyc2]

Darned impressive numbers, maxing out the USB4 link for sure. Apple and macOS really just like the WD nvme controllers. Which brings me to what I've discovered is incompatible about the Samsung (and potentially the Hynix drive as well, though as we've discussed it's not confirmed whether I truly tested it with the latest firmware or not).

Yeah, no luck with the firmware, but what I have figured out is why it hates the Samsung drive especially. It all has to do with power state management...which macOS is not doing a great job with. It appears to be going into a low power state when not in use. Naturally, the writes "wake" the drive up, but then it returns to the low power state and the reads absolutely suffer.

AmorphousDiskMark loads the drive differently, and keeps it in the high power operating state. Blackmagic and regular use just don't put the drive in a high enough power / activity state for reads to perform where they should.

Great glad to hear all is working appreciate sharing your final results with everyone.

Also your further findings on the power states in particular. I am curious how you were able to determine the power states of the drive in different situations?

 

[Flyview]

Informative thread. Thanks for the update. Seeing as you have experience, what would be the benefits of building your own external SSD and an enclosure as opposed to the off-the-shelf externals?

 

[IowaLynn]

OWC has an article detailing some long standing, low level, bugs affecting drives. https://eshop.macsales.com/blog/96475-upgrade-macos-15-sequoia-softraid-8-3/

 

[Flyview]

OWC has an article detailing some long standing, low level, bugs affecting drives. https://eshop.macsales.com/blog/96475-upgrade-macos-15-sequoia-softraid-8-3/

Thanks for the link! I learned that Spotlight causing drives to be un-ejectable has finally been fixed in MacOS Sequoia.

 

[bzgnyc2]

Informative thread. Thanks for the update. Seeing as you have experience, what would be the benefits of building your own external SSD and an enclosure as opposed to the off-the-shelf externals?

It's the classic build versus buy question. Building your own can be cheaper -- perhaps $250 versus $400 for 2 TB capacity and you get precise control over the components. The latter gives the ability to ensure the quality of the components and/or select for trade-offs specific to your needs. Later, you can replace/upgrade the NVMe without discarding the enclosure or vice-versa.

However, you become your own engineer which not everyone wants to do. There's the compatability issues like we've seen in this thread. The standards are all out there but somehow power states or TRIM doesn't work correctly between the particular NVMe, chipsets, and version of macOS. Then there are things like heat dissipation -- different NVMe get hotter than others and different enclosures are better at dissipating heat. How well did you match the two?

The link that IowaLynn just posted highlights what a good vendor/manufacturer will do to ensure a reliable product/solution. They're testing the whole stack and looking for the corner cases to ensure it will work "all the time".

If I didn't have a somewhat technical background and liked playing with computers then I'd probably go the buy route from a reputible vendor that specifically tests their products/solutions with Macs. On the other hand, soldiering through the build route is better than just buying the cheapest thing on Amazon as many people seem to do. I wouldn't do the latter when it comes to storage and data you don't want to lose.