CrystalDiskMark FAQ

Why is my network drive not showing?

If you run CrystalDiskMark with Administrator rights, network drives are not shown. To benchmark a network drive, run the program without administrator rights. When the UAC dialog appears: choose No to run as standard user (no admin); choose Yes to run with admin rights.

Why do my results differ from other benchmark software?

Several factors can cause differences:

• Test data: Some SSDs behave differently with random data vs 0 fill. CrystalDiskMark can use either (Settings → Test Data). Other tools may use only 0 fill.
• Test file size and position on the drive.
• Fragmentation of the test volume.
• Controller and interface: IDE (PATA), SATA, RAID, SCSI, or NVMe and driver version.
• CPU speed and system load.

So it is normal for numbers to vary between different benchmark programs or runs.

The benchmark test failed. What should I do?

Failure is often due to insufficient rights to create the test file on the selected drive. Try running CrystalDiskMark as Administrator (right‑click → Run as administrator). Ensure the drive has enough free space for the chosen test size and is not read‑only.

What does "MB/s" mean?

In CrystalDiskMark, MB/s means 1,000,000 bytes per second (decimal), not 1,048,576 bytes per second. So 1000 MB/s = 1 GB/s in the program’s units.

Are benchmark results compatible between versions?

Results are not guaranteed to be comparable between different major versions (e.g. 7.x vs 8.x vs 9.x). Within the same major version (e.g. 8.0.0–8.0.6), results are typically compatible. Check the official History page for notes.

Can CrystalDiskMark shorten SSD or USB drive life?

Yes. Benchmarking writes a lot of data to the drive and uses up write cycles. Use reasonable test sizes and don’t run benchmarks constantly if you want to minimize wear. For USB flash drives, use a small test size (e.g. 64 MiB or 128 MiB).

What are the units 1GB vs 1GiB?

In the program and documentation:

• 1 GB = 1000 MB = 1000×1000 KB = 1000×1000×1000 B (decimal).
• 1 GiB = 1024 MiB = 1024×1024 KiB = 1024×1024×1024 B (binary).