I'm having a strange performance problem with a 2TB Samsung T7 external SSD on a Windows 11 PC. It is connected with the included USB-C-to-USB 3.2 cable to a USB 3.2 port on the back of the computer. I've also tested other USB 3.2 and USB 3.0 ports with the same result. The drive is not sitting on a hot surface, does not seem unusually warm, and the Windows USB and storage drivers are up to date. I also checked the device policies, including write caching and the removal setting.
The main problem is that read speeds become incredibly slow—almost unusable. A friend connected the same SSD to another computer, checked it with CrystalDiskInfo, and said it worked normally. When I got it back, it performed perfectly for roughly six hours, then suddenly slowed down again while I was playing a game. I'm not sure whether that timing is related.
Samsung's diagnostic software shows good benchmark results only from the test immediately after I got the drive back. The later tests show extremely poor read performance, although the drive-health information appears normal. What could cause an external SSD to work normally on another computer and then become nearly unusable again on mine?
1 Answer
Since a basic health check reports the drive as healthy, run a more thorough diagnostic if the enclosure exposes the necessary drive information. GSmartControl can sometimes perform short or extended self-tests and display an error log. Open the drive in the program, check the Self-Test tab, run the extended test without interrupting it, and review or save the error log afterward. If the program does not offer self-tests, that may be because the T7’s USB bridge does not pass those commands through to the internal NVMe drive—not necessarily because the SSD is failing.
I checked GSmartControl, but it only shows General, NVMe Attributes, and NVMe Error Log. The self-test controls are unavailable, so it looks like this enclosure does not support those tests through USB.