CrystalDiskMark

CrystalDiskMark is a storage benchmarking utility for Windows from Crystal Dew World. It runs a short series of timed read and write tests against a selected drive and reports the results in megabytes per second, alongside IOPS and latency figures. Tests are split into sequential transfers, which show how the drive behaves with large files, and random transfers of small blocks, which better reflect everyday operating system and application activity. The benchmark engine is built on Microsoft's diskspd.

The tool ships with several preset measurement profiles. A peak-performance profile pushes the drive with high queue depths and multiple threads to find its maximum rating, while a real-world profile uses light queueing that resembles typical desktop use. Test size, the number of repeated passes, the interval between them, and the target drive can all be adjusted, and each run can be set to read-only, write-only, or a mixed read/write ratio. Results can be copied out as text or saved as an image for sharing.

The program is distributed as an installer or a portable archive, and runs on Windows from XP through Windows 11 as well as Windows Server releases, with x86, x64, and ARM64 builds. Besides the standard interface, the developer publishes two alternative themed editions with illustrated skins; they are functionally identical to the standard build.

It is a good fit for anyone verifying that a new drive performs as advertised, comparing an SSD before and after a firmware update, or checking whether a USB stick or SD card is as fast as its packaging claims. It is less suited to sustained endurance testing or enterprise storage qualification, where longer-running and more configurable tools are appropriate. Note that repeated write benchmarks consume flash write cycles, and scores are not comparable across different major versions of the program.