Quick answers

These notes cover the questions we see most in support mail. Still stuck? Browse the forum or jump back to the overview.

Health & status wording

What does "Caution" or "Bad" mean in CrystalDiskInfo?
Those labels fire when one or more SMART attributes cross thresholds defined by the drive or by the app’s rules. Treat them as a prompt to clone data and plan a replacement—not as a guarantee of instant failure, but never ignore them.

Odd numbers & firmware gaps

Why do "Power On Hours" look wrong on an old Maxtor?
Several legacy Maxtor firmware builds encode elapsed time in vendor-specific units. Compare trends rather than absolute hours, and lean on reallocated-sector counters for the real story.

Why is "Buffer Size" unknown or weird?
Many bridges omit cache reporting from IDENTIFY/SMART pages. CrystalDiskInfo prints what the bus returns; blanks here usually mean the drive simply did not volunteer the field.

Why is the "Rotation Rate" not displayed for my disk?
SSDs have no rotation rate. Some HDDs do not report this field in their identify data. If the drive is detected and S.M.A.R.T. works, other data is still valid.

Detection & Troubleshooting

Why does CrystalDiskInfo say "No Disk Found" when I open the program?
Run as Administrator, ensure drivers are not blocking access, and check that drives are visible in Windows Disk Management. External USB drives may need to be connected before starting the program.

Why are my Samsung HD155UI or HD204UI drives not showing up in the list?
Some Samsung models have known compatibility issues with certain SATA controllers or drivers. Try updating chipset drivers or using a different port; check the forum for model-specific workarounds.

My external USB drive isn't responding or showing data. How can I fix this?
Ensure the drive is powered and recognized in Windows. Enable USB/IEEE 1394 options in Advanced Features if needed. Some USB bridges do not support S.M.A.R.T.; try a different enclosure or cable.

General

Does it work on Mac/Linux?
No, CrystalDiskInfo is a Windows-exclusive utility (XP through Windows 11/Server).

Is it free?
Yes, it is 100% free and Open Source under the MIT License.