Source: http://feeds.gawker.com/~r/lifehacker/full/~3/okQrHFXtV6M/hd_speed-benchmarks-your-disks-and-drives
Windows only: Don't mutter to yourself about how slow your drive is, benchmark it to know exactly how fast it is (or isn't) moving. HD_Speed gives you real-time feedback on any drive's transfer speed.
All disks are not created equal, so if you have a nagging feeling that one of your flash drives is under-performing, it probably is. HD_Speed is a lightweight (82k!) portable application that monitors disk read and write speed in real time to help you assess disk performance. You can use HD_Speed on virtually any media: floppy disks, CD/DVD drives, hard disks, and flash-based media like USB drives and SD cards. While the real-time testing is useful for instant feedback, if you'd like to test for problems cropping up over time you can set the duration of the test and tell HD_Speed to log the process for later review. HD_Tune is freeware, Windows only.