T7 Shield 4TB – Firmware FXI72P2Q Severe Write-Speed Regression (Cross-Platform, Post-OS Updates)

[scineman]

Hi Samsung team,

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.

[scineman]

Both tested under identical conditions (same system, same cable, same port).

The good 2 TB benchmark (941/922 MB/s)

The bad 4 TB benchmark (~2 MB/s)

[Arbee]

Facing a similar issue with my T7 Shield on FXI72P2Q

Versus my regular T7 on FXG42P2Q

[scineman]

Yeah, I think it is like a perfect storm between the bridge controller T7 Shields use, that firmware, and possibly changes in windows and mac os on how they handle drives like this. All 4 of the t7 shields I have are acting exactly the same.

[Arbee]

Yeah, there has been noticeably different performance with this T7 Shield since I bought it probably 16mo ago. Just chocked it up to variance, but it's been worse in the past few months. I'll have to check another one that I've got later this evening and check fw/performance on it.

[Arbee]

Even weirder performance on my other T7 Shield. Same setup (40Gbps cable + TB4 port)

[scineman]

So I spoke to technical customer support, and other than suggesting I try reformatting and re-initializing the drive or sending in to rma, there wasn’t much else he could suggest. I explained there was another thread where they tried both and didn’t have results. I managed to get the email I could then request to forward to engineering dept, but I didn’t get to sending that. Will send soon and post any updates if any.

 It’s a bit frustrating when trying to troubleshoot this and getting messages like:

”The Samsung T7 SSDs are consumer SSDs, due to this Samsung does not offer failure analysis, if this is what you are requesting.”

 When they clearly don’t promote their T7 shield (or price them) as such. A lot of professionals I know have been trusting these, and now I have serious doubts.

[Memory Product Expert -1]

Hello scineman , 

Have you contacted the Samsung warranty/technical support department for memory products? 
Maybe they can have the your drive and firmware tested to find out what's going on? 

[scineman]

I'm trying to reach the right person/dept. but Samsung seems to make it a maze to navigate through. I've spoken with tech support, but they were unable to help remotely or be able to point me in the right direction. Another contact could only RMA the drive, which is pointless as explained in another thread on this forum. It's affected four of my drives which hold about 10TB collectively, so sending in a drive for testing is really a last ditch resort. I have a number I need to try next, so hopefully I'll have some luck there.

[nirmalkurienmathews]

I have this same issue with my T7 and T9. Samsung please fix it through firmware update.