T7 Shield 4TB drives were FAST - Now Extremely SLOW

[cableguy1970]

I have (4) T7 Shield SSD Drives, 4TB size, and all four used to work flawlessly. Now attempting to save data to any of the drives they are going slower than dialup. Over 4 hours to save 4GB. I've used Samsung Magician to ensure all drives have the latest firmware (FXI72P2Q). It's odd that they all are performing exactly the same way. I've used two different Mac computers with the same results: 16" MBP M3 Max, 48 GB Memory and Sequoia 15.4 installed. 2nd Mac is a 16" MBP M2 Max, 96 GB Memory installed. I also have a Samsung T9 SSD, and it's just as slow. Any help would be greatly appreciated.

[TheBiles]

I'm getting the exact same issue with a T9 on my MacBook Pro M4. Supplied cable, tried all ports, updated SSD fimrware. Nothing.  2 MB/s write speed. Confirmation from Magician:

[262626]

My solution to a 6 months old T7 4TB (2.6TB full) with extremely slow 2MB/s write speed:

1. Reformat
2. Rewrite 2.6TB data while monitoring temperature with Samsung Magician app
3. Leave T7 connected after write so that data in SLC cells can be transferred to TLC/QLC cells
4. Not connecting this T7 to my old iMac with USB 2 ports, which might have caused the slow write problem
5. Normal write speed for 3 weeks so far
6. YMMV

[262626]

FYI! As long as I don't connect my one T7 4TB SSD (65% full) to any USB 2 port, the USB 3 write speed remains normal. After connecting it to USB 2, the USB 3 write speed slowed to a crawl. Hopefully, a firmware update will fit it in the near future!

My T7 2TB and T5 500GB don't have this 2MB/s slow write speed issue!

[Kyblik81]

i have the same problem for about a year, when i want to do bigger backups of the files, not for just every so often connectiong SSDs to get some refreshing electricity. first few weeks, months both T7 and T7 Shields worked nicely, but after some time, its just 1,8Mb/s transfer speed. checking that performance boost in Device Manager is short time workaround, which will expire with every other usage. only thing it helps, is just let it just write new data with that crazy speed and it will go up in several, maybe 10, or 20 minutes, for the maximum. when i copy something 1,5GB it stays on 1,8Mb/s speed for its entirety, but if i copy something lets say 16GB, it takes that 10 minutes slow speed, but after some time it just finishes in top speed in a minute.

but defo, Samsung should do something about it. until then, im buying Verbatim, or even SanDisk...

[Kyblik81]

and update on this. now im copying 70GB, mostly music files, all mp3, flac or wav, and it goes in cycles - slow, up to maximum for few tens of seconds, then again slow, up again, slow down, up and down. whole 70GB done in about 30 minutes...