I’m reporting a reproducible firmware-level issue affecting multiple T7 Shield 4TB/2TB drives (firmware FXI72P2Q) across both Windows 11 24H2/25H2 and macOS 15 (Tahoe) systems.
Summary
Write speeds drop from ~900 MB/s to 2 MB/s or freeze completely.
The issue reproduces on multiple systems and USB controllers (Z790 Aorus Elite AX, Intel Maple Ridge TB4 card, MacBook Pro M3).
The same ports, cables, and systems work normally with other drives (SanDisk Extreme, Crucial X10 Pro, Samsung T7 2TB).
Affected drives show constant blue LED blinking even when idle—unaffected units turn off the LED after I/O.
There are reports posted within the last 48 hours of people suddenly not being able to use the drive to record on their professional cameras where they had previously had been able to do so.
Testing & Comparison
Benchmarks (Samsung Magician / Blackmagic Disk Speed Test) confirm the regression.
Newer 2 TB T7 Shield (FXI72P2Q_3603_02000101) units sustain normal 941 MB/s read / 922 MB/s write.
Older 4 TB and 2 TB units collapse to 2 MB/s and cause system hangs during file copy.
Reformatting, switching ports, drivers, and OS builds does not resolve the issue.
Updating BIOS, chipset, and to Windows 11 25H2 made no difference.
Hypothesis
This appears to be a firmware-level issue in the ASMedia ASM2364 bridge controller used in the 4 TB T7 Shield. When the host issues modern UASP 1.1 / USB4 power-management flush-and-suspend commands, the controller enters a non-idle state and throttles all subsequent writes. This aligns with other reports on the Samsung Community (thread #3189332) and across Reddit and Blackmagic user forums.
Request
Please forward this to Samsung’s firmware or product-engineering team for verification. I’m happy to provide full logs, benchmarks, and system details for reproduction.
Thanks for your time and attention to this — this issue affects not only file transfers but also real-time camera recording workflows that depend on the T7 Shield line.
In order to help out, How do you know this is a firmware issue? Are you able to provide more details about your system and your current test results?
Unfortunately, many users are not aware that a performance issue with a portable SSD can be caused by many things such as incorrect settings or optimization that may need to be done on the SSD such as TRIM.
If you are having issues and you believe its the firmware, please provide all important information that led you there, otherwise no one will be able to assist or investigate further..
Let me explain my situation, I got 3 Samsung T9 (2TB & 4TB) and 4 Samsung T7 Shields. I get good speed at the beginning of each SSDs. Now I only get less than 2MB speed. I think this massive speed reduction is not due to low disk space because one T9 shield I'm using currently don't have any issues even though there is only few Megabytes of free space in it. I get good speed with it.
I experience this poor speed only after not using the drives a month or so. The one with good speed, I'm using it frequently for reading and writing.
I enabled TRIM, I do TRIM manually, updated to latest firmware and also enabled performance mode. I am sure this poor speed reduction is related to some firmware issue. This issue is being reported globally across reddit and other forums.
I can provide more details when requested. I just want a proper solution or a technical reason behind speed reduction.
Help me to revive my SSDs. I don't want to format or return them as I got Important files stored in them and I don't have other drives to do the backup.
Thanks for the update, still not sure what computer you are using? Have you received any error messages stating or showing that firmware is the cause of this? Can you at least provide a picture of the slow speed so we can see how your testing it?
It seems a lot of users blame the firmware but have nothing to show that the firmware is the cause of the problem. Most users just say that its all over the internet, yet nothing shows issues with firmware specifically or they use AI for troubleshooting 😑
Also, how are you planning on troubleshooting if you can't at least format the drive? Formatting is one of the most basic troubleshooting steps to diagnose any storage drive SSD or HDD.
I buy External SSDs for backing up important files. How will anyone know that external SSDs needs to format everytime when there is an issue?! Either it's Firmware or Samsung's problem. Because I don't have this issue with other companies External SSDs.
Anyone that has at least a decent amount of experience dealing with storage devices, will let you know, that formatting, is one of the easiest ways to know if a performance issue is being caused by a "software" issue such as a bad volume or partition or incompatible format settings.
A lot of users think that formatting an SSD just means "erasing all the data on the product" That is not the case. For example, if you are using a storage device on an Apple computer, Apple recommends using APFS format, this is because they know their OS is designed to organize data most efficiently if you are using their preferred format setting. That change alone can make a huge difference in speed specifically.
I understand all that. You think I post here asking for help or want to know the reason without trying to make sense of what's happening which is so obvious to anyone handling computers these days?
There is another thread posted here about this same issue. I don't have to post any screenshots about my problem because I am facing the same problems as mentioned by other users already.
If you ask me specifically about a screenshot or information which is not posted by others... I can provide them.
No worries, If you do not want to post any information for your issue specifically as other users have already provided the details for their issues, that's completely understandable,
Hopefully, the information the other users have posted will help get to the source of the problem.
So far it's still been silence from Samsung about this. I never added to my post, but I ended up speaking with a Microsoft tech, and he said he personally was experiencing the same problems, and they we're looking into it. Something around the time of the previous firmware and something with windows/Mac Os updates broke things with these Samsung drives. I ended up having to dump all the data on each drive to another working one, and not just reformat, but completely reinitialize the drive, after a reboot it started working correctly. We shouldn't have to do this with relatively new drives, especially when it's 10TB or so of data to have to move around. I did notice a recent firmware update specific to shield t7 drives (within the last week or two), but I have yet to test on one of my remaining drives with the issue. I'll check soon and report back. Unfortunately I could not find a change log or documentation on this last update, so no idea what it addresses. Either way, the issue seems systemic to these types of drives, since the write speed is identical on all, and other drives are working fine.
Just out of curiosity, do you know what format style the SSDs you have are currently using? Would you be able to post pictures of your benchmark results too ?
I'm not sure what you're asking here, you mean format type? It's exfat if that is your question. I already posted pictures of the benchmarks as I am the author of this original thread. Screenshots are not going to help anyways, they pretty much show what everyone is seeing, which is that the write speed get stuck at sub 2mb/s speeds.
