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.

[Moreny]

After about a year and a half, my T7 Shield 2TB SSD started writing at ~2 MB/s.

I used it rarely (usually once every ~2 months), mostly to transfer files. I occasionally connected it to a PC (Windows 11 Pro, Z690 mb) and a MacBook Pro M3 Pro.

As i understand this is a global issue, as there are tons of people complaining about it another forums.

It's not a cable or port issue. Something's wrong with the drive itself or firmware. I tried different cables and different PCs. The speed was initially around ~2 MB/s, but if I waited 2-3 minutes, it started to increase sharply for 500+MB/s. This issue specifically with writing. Reading always is normal (fast, about 800+ MB/s). What could be the problem, and is there a solution?

I updated the latest firmware (FXI72P2Q) via Magician, but it didn't help. I tried leaving it connected to the PC for more than 2 hours (without writing or copying anything) – it didn't help. The speed always remains low at first, ~2 MB/s. There's no password (encryption) on the T7. It's never been set. I've tried various high-quality, certified Thunderbolt 4 cables (USB4, USB-C 20GB, etc.). The temperature is always normal. Is formatting the drive really the only option?

But that's a temporary solution, and I understand the problem might reoccur later? Is there any way to fix it without transferring data or erasing the drive? It's also worth noting that I've never filled the drive to even 80%. The maximum I've ever filled it to was ~35%. I think I've written no more than 1000 GB of data to it in total over the entire time I've been using it.

I tried connecting T7 Shield and to PC and a MacBook Pro - this issue is the same everywhere.

P.S. I also read forums where people noted: he's tryed returned their SSD's via RMA—they were given new ones, and after a while, the new ones SSD also started working with low write speed again (about ~1-3MB/s). So, most likely, the issue is with faulty firmware.

Will there be a fix?

[Memory Product Expert -1]

Hello Moreny 

Have you confirmed that formatting the SSD is a temporary solution? How long has this solution worked for you?
For example, If you have formatted your drive, does the issue come back within a month or less or after a certain amount of writing?

[Moreny]

What I meant was that I found a lot of reviews from people all over the world, from Reddit, another hardware forums to YouTube. Probably over ~100+ people (just the ones I found during a quick search) throughout the last year have complained about the same issue: after a while, their T7 Shield external drives would start writing at ~2 MB/s.

The only solution that worked (other people wrote this, I haven't personally tested it) - was formatting the drive (with unchecking the "quick format" option). After that, they noted the SSD resumes its normal speed of ~800 MB/s. However, many also noted that this is a temporary solution. I don't know how long this solution lasts. But people have clearly noted that after a while, the speed returns to 1-2 MB/s.

Personally, I haven't formatted my T7 Shield yet. First, I need to transfer my data and files from it somewhere, and I don't have that option right now. That's why I decided to post in this thread and ask how long to wait for a fix? To be honest, I really don't want to format my SSD and erase the data.

I'd like to understand what's going on. Will there be a fix? One thing is clear: this is a global issue. As i see many people have been reporting it for years. And there are still no official comments or decisions from Samsung.

[Memory Product Expert -1]

Hello Moreny,

Well, the issue here, is that low performance can be caused by several different factors, how has it been confirmed that Firmware would be the cause of the issue? 

For example, if someone has a bad drive that is physically defective, how would a firmware update resolve this? 
If your not willing to format your SSD, how will you find out if there is data on the drive that is corrupt or stored improperly that is causing a slow speed?

For example, have you tried running a disk optimization on your drive? This is something that should be done on any SSD, but if its not being done by the OS, then performance will suffer and the user will blame the SSD itself. 

[scineman]

No, this isn't user error. We need to get off that as a possibility. I work with media and drives on a day to day basis. None of my other drives are exhibiting this issue, and yet all four of my Samsung T7 shields have the identical issue. These were all purchased at different times over the course of a year and a half, so the chances of coming from the same batch are slim. Two of the drives had the date written to once, and the left alone for 4-5 months. While re-initializing seems to have worked (for now) this is not something we should have to be doing, especially if we're talking about a 4TB drive. The issue is clearly systemic and either a result of the firmware, or the controller board these drives are using. Also, these all have optimization being handled by Samsung magician since day one, so that variable is moot.

[scineman]

I thought about it some more and wanted to follow up with some details because this issue is showing up across multiple T7 Shield units, and the symptoms don’t line up with normal user-side filesystem corruption or anything that would be fixed by “disk optimization.”

I have several T7 Shield drives (2TB and 4TB), all purchased at different times. Two of them developed the same write-speed issue after sitting unused for a few months. They were written to once, safely ejected, and not touched again until recently.

When I reconnected them, read speeds were perfectly normal, but write speeds dropped to 2–3 MB/s. The blue activity light blinks constantly even when the drive is idle.

To rule things out, I tested on:

• Windows 11 (multiple machines)

• macOS (M3 MacBook Pro)

• Different USB controllers, including Thunderbolt 4 and motherboard ports

• Different cables

The drives behave the same on every OS, which rules out OS-level corruption or cables.

Here’s the important part:

A simple quick format does NOT fix the problem.

However, deleting the partition entirely → recreating it → then doing a quick format does restore full write speeds. (or as others have pointed out only after a low level format)

This behavior strongly suggests that the issue is not normal data corruption in the user partition. If the filesystem was corrupted, a quick format would have fixed it, but it doesn’t. Only a full partition-table rebuild, possibly triggering a full-range TRIM, clears the condition.

On top of that, leaving the drive plugged in for several hours (doing nothing) also restores full write performance, which points toward the controller trying to recover or rebuild something internally.

These symptoms match:

• a stalled or inconsistent free-block pool

• a stuck garbage-collection state

• or a corrupted FTL metadata journal

All of those live inside the SSD firmware itself, not in the filesystem.

So honestly, everything points to a stateful firmware issue affecting the FTL or TRIM-handling logic. There are multiple reports in the Samsung Community, Reddit, and even creators using these drives with cameras seeing identical symptoms.

Also, you mentioned a "bad drive", but a bad drive would likely exhibit other issues like slow reads as well or file corruptions, not just write issues.

[nirmalkurienmathews]

Hi, I don't know what's real problem. I think these SSDs needs some charging once in a while. There is another thread here about T7 or T9 shields, mentioned about keep the drives connected to the system for half a day or so. It helped me. 

The problem what I am facing is caused after not using these drives for months. So, what I am doing now is keeping those low performance drives connected to my Windows system for few hours, Running performance benchmark each hour in Magician. I am getting good speeds now. I can see performance increase in each performance test. Other than formatting, I think that's one of the solution for low performance drives. 

You can check the other thread explaining user's test.

[DaRealBear]

Same problem, suddenly slower than molasses. Drive was about 75% full, I deleted some large files, no change. Very frustrating. I paid good money for the drive because I trusted Samsung quality, only to be disappointed.