My lightly-used 4TB Samsung T7 external SSD today exhibited the weird behaviour I’ve seen a few other people mention, where it starts only writing at about 2 MB/s and becomes unusably slow for reads if any writes are happening.
It feels like a firmware bug instead of a hardware issue, maybe related to TRIM or some other kind of optimisation it performs.
I bought the T7 because my older T5 has been brilliant, but after this weirdness with the T7 I might avoid Samsung SSDs.
@eurozerozero Forgive me here for interrupting with a non-answer, buts is not quite 7:00am here and I’m not really awake yet.
I seem to recall recent macOS fails to enable TRIM support on external non-Apple SSDs, and that causes that very problem.
There is a way to to turn it on from terminal.
You might start looking for info on that and see if it fits your scenario.
@LoneLocust Yeah, I believe macOS doesn’t support TRIM over USB by default (only over Thunderbolt) and the T5 and T7 are USB-only, so they wouldn’t be using it.
But apparently these drives do their own “internal TRIM” (where they try to achieve the same result) in the background to maintain performance over time.
People suspect the T7 issue might be something to do with that process occasionally not working properly. The workaround seems to be formatting it and letting it sit for a while.
@eurozerozero Sorry that didn’t help out.
Pity. I was hoping to score a “win” before breakfast today. :-)
@LoneLocust And that worked for me: right after a format it was still terrible performance, then after leaving it powered and idle for a while it suddenly was back to full speed.
Now the question is whether it’ll stay that way. For some people it only happens once and for other people it keeps happening 😬
Apparently the Shield version of the drive has the same issue. Annoying! My T5 has never had any issues so I felt safe buying the T7!
@eurozerozero Frustrating, isn’t it?
I can’t remember how many times over the years I’ve bought something thinking, “The older model has been great!” only to discover they’ve “improved” it in some way that isn’t an improvement.
I hope it stays fixed.
eurozerozero
Eugene Glover