USB3 key speed on USB2 port


Hi all
I have one question. Why during formatting USB3 key (zeros - slow formatting) formatting speed will drop after 1G formatted disk from 24MB/s
to lowest speed 2,8MB/s. And USB2 key formatting the same speed (about 16MB/s) all USB2 key. I use Linux mint and program to be formatted “Disks” PC 2,8GHz dual core and 2Giga ram.
Why it slows down during formatting and what can I do so USB3 key won’t slow down ?
Thank You


There could be multiple reasons for this behavior:

  • USB 3 flash quality
  • Speed of connection
  • USB module/driver in use
  • chipset compatibility
  • and more

Have your tried different model of USB 3 flash drive to see if you get the same result? This would help us to narrow down the possible causes.

How did you measure the write speed? Can you try to run some command line performance tests. For example: Hard drive speed test using Linux command line and hdparm