Samsung T7 2TB slow R/W speeds

[Fishrrman]

c.ober wrote:
"2 of my 3 T7 shield SSDs have recently became very slow, like 2-3 MB/s read and write speeds. After reformatting speed is back to normal, just to become slow again after a few weeks."

Please see this post I put up:

https://forums.macrumors.com/threads/slow-external-drive-on-sequoia-15-2.2445630/

I was having (and still see, now and then) exactly the same problem.
When you first connect the t7, write speeds are at a crawl.
Sometimes they will "pick up to normal", after several seconds have gone by.

As in your case, reformatting didn't help.
Updating the firmware using "Samsung Magician" worked, kind of.

This doesn't seem to affect READS.
Only WRITES.

I still use the t7's for backup and archival drives.
I've also been using a Crucial X9 -- no problems at all.

 

[c.oberschneider]

Thank you.
I also found this thread on reddit:

https://www.reddit.com/r/mac/comments/16x7j8v/samsung_t7_external_ssd_extremely_slow_like_3mbps

What worked: Adding a new 200GB partition of exFAT, then doing a speed test via BlackMagic on that partition. The first pass was 5MB/sec, but after that TRIM or SLC caching seemed to fix itself and speeds returned to normal on the APFS and exFAT partition. Now I'm back to 800-900MB/sec writes, and 600-700MB/sec reads.

...and it worked! Speeds were back to normal after creating the exFAT partition. The bad news: after deleting the partition, it was dead slow again. But just now I let Black Magic Disc Speed test run for about 5 minutes, we're back to 700 MB/s again...

 

[macrumorsnumpty]

I had just noticed my M2 MacBook Pro Max (15.4.1) was struggling with the T7 and T9 Samsung SSDs. writing was at the 3.2 - 6.4MB/Sec. Either formatted in APFS or NTFS or Ex-Fat, made no difference. the T5s (APFS) were fine with 512MB/sec read and write speeds. I installed Samsung Magician (OSX) and updated all of the drives. The T5s were still fine. If I connected the T5s directly to the thunderbolt port, with any type of cable the R/W speeds were 430MB/sec. Connect the T5's up to a USB hub then the speeds increase to 512-530MB/sec. The T7s and T9s still were super slow. I formatted the T9 with APFS and bingo 923-940MB/sec. I assume when I copy the info from the T7s and then wipe, everything should be back in action.

What is frustrating is my Dell Latitude 5590 can read and write these drives at 1400MB/sec.