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...

[norbertss]

Does anyone have any information on how to solve the problem?

[usernZRSD2zDkA]

Just chiming in that I've had this issue as well, mostly on a 2TB T7 shield that isn't used much. Mostly on a Windows 11 laptop.  I was all set to RMA it but then I did a full erase-reformat-reload the drive, and it worked fine. I didn't RMA it as I figured Samsung would get it back and say it was fine and do nothing. So I used it, for a while. Then I didn't use it for some months, and it had the same issue. I erased-reformatted-reloaded it again, and it worked fine, again. Very very strange.

My T7 Shield 4TB that I use as a "hot" backup drive (i.e., gets used a few times a month for a while) hasn't had the problem.

It seems to be an issue when you let the drive sit for too long without being powered? Samsung support seemed to have no idea when I was talking to them about the initial RMA but that seems to be the usual strategy.

Really hope it's a firmware issue that eventually Samsung can figure out although these drives are getting older so they may not be looking at them, which would be unfortunate.

I should add my 2TB which has had the issue was bought in 2022, and now out of warranty. The 4TB that I haven't seen the issue on, was bought in 2023.

[c_oberschneider · Accepted solution]

I've had the same problems with all 3 of my 4TB T7 shield SSDs getting slow read / write speeds on my M1 Max MacBook Pro, while my other SSDs (SanDisk and Angelbird) are all working flawlessly. Just today I stumbled upon a possible fix in a reddit thread here: https://www.reddit.com/r/mac/comments/16x7j8v/comment/m9nfvm3/?utm_source=share&utm_medium=web3x&utm...

And that did it for me! All 3 drives are back to normal speeds, also after unplugging / restarting. 
I'd love to hear if that solves the issue for anyone else as well.

[user_dsf98yw5n4t]

OMG THIS SOLVED THE PROBLEM!!!! THANKYOU THANKYOU THANKYOU THANKYOU!!!!!  EVERYONE CHANGE YOUR DISK PERMISSIONS TO READ & WRITE!!!  I can't believe something so simple fixed it!!  I knew there shouldn't be an issue, I formatted my drive on my Mac and this is an SSD so there shouldn't be any issues with the write needle or read surface damaging 

Salute!