sdspeed

sdspeed lets you speed test your USB and SD Flash drives cards. It can check SD flash cards, USB flash drives, pen drives, and memory sticks.

It does an extensive write and read tests; every single bit is tested to check if it can be written and read. It does this by testing for counterfeit or fake USB flash drives, and checking your USB Flash Drive for errors. It works basically with any USB memory device like USB hard disks.