I bought a Sandisk Ultra Dual Drive Go 256GB USB 3.1 Stick.
The writing speed is unbelievably slow. In both USBA and USB-C connectors.
When I write from my new Lenovo laptop ThinkPad T14s Gen4 (32GB/1TB), the usual speed is under 10MB/s.
In some cases it may reach 30MB/s, but only for a few seconds, it goes down to <10MB/s. Sometimes it stalls to 0 for a few seconds.
It is formatted as exfat, but I also tried NTFS, even FAT32.
It is practically unusable.
This isn’t a fault with your unit. It’s how the SanDisk Ultra Dual Drive Go is built. It shows good read speeds, but the write speed is weak and unstable. You get a short burst at 20–30 MB/s, then it drops below 10 MB/s or pauses because the tiny internal cache fills up. Changing the file system or using USB-A vs USB-C won’t fix it. It’s fine for quick transfers, but frustrating for regular use. If you can, return it. For good performance, look at a SanDisk Extreme, Samsung BAR Plus, or better, a small external SSD.
Thank you very much for your reply. Unfortunately, I can no longer return it, as yesterday afternoon I threw it out of the window—and I mean that literally, I’m not joking.
That said, I believe it has a design flaw. No matter how small the internal cache may be, it is unacceptable to send a one-gigabyte file to it and then stare at the screen for about twenty minutes while it sits at 0 MB/s. Something is clearly wrong in the design.
In any case, it no longer matters. I will buy something else to get my work done.
Totally get it. Staring at 0 MB/s while a simple 1 GB file crawls along would drive anyone up the wall, so your reaction is honestly relatable. You’re right, too. Regardless of specifications or cost-cutting, that kind of behavior is just unacceptable from a modern USB 3.x drive. At least the upside is you won’t waste any more time fighting it.
Have you used CrystalDiskInfo to check the health of that USB stick? If you continue to experience slow read/write speeds with your disk/USB drive, you can try updating outdated or incompatible drivers, testing the read/write speed again with professional disk tools and freeing up more space, checking for high CPU usage, and performing disk defragmentation, etc. (You might also want to learn more: How to Fix Windows SSD Transfer Speed Drops to 0/Is too Slow)
