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.
