Do USB drives degrade or throttle?

mipial · October 27, 2018

Hello all.

I have had a Sandisk Ultra Flair for some time now. It has always been fast enough to run portable apps from it even on USB 2.0 without any performance issues.

Last week I decided to encrypt it using BitLocker. It took a few hours. It saved the data and everything, but I started getting performance issues with long-lasting freezes on the portable apps.

I assumed it had to do with the encryption, so I re-formatted it. I used NTFS instead of exFAT so that I could connect it to my Synology and set it to copy almost 40gb back into it (I wanted to avoid interference from Windows processes). It took more than a whole day!!!

Worried about that, I used Crystal Disk Mark to verify the transfer speed. It was depressing.

When compared to a cheaper 16gb drive, it was obvious that something wasn't right.

I fired up Paragon Partition Manager, erased the pen drive's partition, rebuilt the MBR and created a new exFAT partition. Then it gave me the results shown.

So I thought it had been repaired, but I'm copying the files back to it and while it started at almost 9 MB/s, after a few seconds it dropped to around 200 KB/s with both large or small files.

The drive has always gotten hot while working, but I have never before witnessed a perfomance loss.

Do these drives degrade or throttle? Should I assume it's failed?

Thanks