USB3.0 flash drive is very slow. It may be a driver problem.

[mooinghorse]

I recently got two new USB3.0 drives ( specifically Lexar LJDS75-32GABNL ). They were both fairly slow to begin with. I reformatted from the default of FAT32 to exFAT, which seemed to fix the problem at first. Now they're being slow again (like 1 Mb/s or less).
I am running Windows 10, and I know my laptop supports USB3.0. When I look in the device manager, the driver it shows for the flash drive is from 2006 and when I click the tab to enable readyboost, I get a message saying the device is plugged into an unsupported port, as readyboost requires USB2.0 or greater. This implies my driver is really old, but when I try to update, Windows says the drivers are up to date.
At one point, I was able to transfer a 3GB file at 20Mb/s and on another file I think it went much higher for a brief period of time.
Any ideas on what's happening here? I can post more details if that would help.

 

[jsmithepa]

You must use the driver provided by your laptop vendor, NOT Microsoft, and it better say CERTIFIED FOR WINDOWS 10 and has a built-date of no more than 6 months old.