CrystalDiskMark is a storage benchmarking tool that allows you to test the read and write speed of hard drives, SSDs, memory cards, USB flash drives, and even network drives.
Although its appearance is simplistic, it is a fairly complex software, with optimized read and write algorithms.
It is capable of performing read and write tests on different block sizes, ranging from 512 bytes to 32 MB, and with different test patterns, including random and sequential.