sdspeed lets you verify the integrity of a flash SD card or USB device. You can test not only SD (secure digital) cards, but also USB flash drives, even hard drives that are connected via USB. It also provides benchmarks, such as the speed of a memory card, an SD card speed test, a flash card read-write test, and SD-card speed or measurement of micro SD performance. It is the only product that measures the read and write rate, testing every bit of your SD memory card.