Frequently Asked Questions

Why does CrystalDiskMark not show my network drive?

If you run CrystalDiskMark with Administrator rights, network drives are not displayed. To measure a network drive, run the program without admin rights. When the UAC dialog appears: Yes = with Administrator rights (no network drives), No = without (network drives will appear).

Why do results differ from other benchmark software?

Results can differ for several reasons:

• Some SSDs behave differently with test data (random vs 0 fill). Other software may use 0 fill only.
• Results depend on test file size, test file position, fragmentation, and the controller (IDE/PATA, SATA, RAID, SCSI, NVMe) and CPU speed.

So small differences between tools are normal. Use the same tool and settings when comparing drives.

Benchmark test failed – what should I do?

The benchmark may fail if the program does not have enough privileges to create the test file on the selected drive. Run CrystalDiskMark as Administrator (right-click the executable → Run as administrator) and try again.

What does MB/s mean?

In CrystalDiskMark, MB/s means 1,000,000 bytes per second (decimal), not 1024×1024. So 1000 MB/s = 1 GB/s (decimal).

Are benchmark results compatible between versions?

Benchmark results are not compatible between different major versions (e.g. 7.x vs 8.x vs 9.x). When comparing results, use the same major version and similar settings.

What test size should I use?

Default is 1 GiB. For slow storage (e.g. USB flash drives or old HDDs), use a smaller size (e.g. 64 MiB or 128 MiB) so the test finishes in a reasonable time. For fast NVMe SSDs, 1 GiB or 2 GiB is typical.

Does CrystalDiskMark shorten SSD or USB life?

Benchmarking writes a lot of data to the drive. CrystalDiskMark may shorten the life of SSDs and USB flash memory because of this write load. Use it for occasional tests rather than constant stress runs.

What is the difference between Standard, Aoi, and Shizuku editions?

Functionality is the same. The difference is visual themes and appearance. Standard has the classic look; Aoi and Shizuku editions offer alternative themes. Choose the one you like.

Can I use CrystalDiskMark on a USB flash drive or external SSD?

Yes. Select the USB or external drive from the drive list. Use a smaller test size (e.g. 64 MiB or 128 MiB) so the test does not take too long on slower media. Make sure no other program is actively using the drive.

What is the difference between Peak and Real World performance?

Peak performance uses settings that often give the highest numbers (e.g. queue depth and thread count tuned for maximum throughput). Real World performance uses a more typical workload mix, so numbers are usually lower but closer to everyday use. Use Peak to compare hardware; use Real World to set expectations for normal usage.

Is CrystalDiskMark safe? Does it contain malware?

CrystalDiskMark is widely used and trusted. Download from the Microsoft Store or from our download page. The installer may offer optional bundled software; read each step and decline if you do not want it. The ZIP version has no installer and no bundling.

How do I save or share my benchmark results?

Use File → Copy to copy the result to the clipboard, then paste into a document or forum. Use File → Save (text) to save as a text file (UTF-16LE). Use File → Save (image) to save as PNG, JPEG, or BMP for screenshots and reports.

Why are my sequential speeds lower than the drive's advertised speed?

Advertised speeds are often from ideal conditions (empty drive, specific test). Your result can be lower due to: drive already in use, SATA vs NVMe link width (e.g. x2 instead of x4), thermal throttling, older driver, or different test size. Run with minimal background activity and ensure the drive is not too hot.

Does CrystalDiskMark work on Windows 11?

Yes. CrystalDiskMark supports Windows 11. Use the latest version (e.g. 9.x) for best compatibility. If you see UI issues, try the ZIP (portable) edition or check for updates.

What is IOPS and when does it matter?

IOPS means I/O operations per second. CrystalDiskMark can show results in IOPS (change in Settings if available). IOPS is especially useful for random 4K tests: high IOPS mean the drive handles many small reads/writes per second, which matters for databases, virtual machines, and heavy multitasking. For large file copies, MB/s or GB/s is more relevant.

Why do my results drop after several runs?

NVMe and some SATA SSDs thermal throttle: when the drive gets hot, speed is reduced to protect the hardware. Let the drive cool for a few minutes and run again. Improving case airflow or adding a heatsink can help. CrystalDiskInfo (from the same developer) can show drive temperature if you want to monitor it.

Can I run CrystalDiskMark from a USB stick without installing?

Yes. Download the ZIP (portable) version, extract it to a folder (including on a USB drive), and run the .exe from there. No installation required. You can then benchmark other drives on the same PC. Run as Administrator if you need to test drives that require elevated access; run as normal user if you need to see network drives.

What is the difference between Read and Write in the results?

Read measures how fast the drive can read data (e.g. loading a game or opening a file). Write measures how fast it can write data (e.g. saving a file or installing software). Both matter: read often affects boot and load times; write affects installs, downloads to disk, and file copies. Some drives have much higher read than write; CrystalDiskMark shows both.