CrystalDiskInfo Health Status & S.M.A.R.T. Values Explained
Understand what a Good, Caution or warning status can mean, which S.M.A.R.T. values deserve attention, and what to check before assuming a drive is failing.
How to interpret the health summary
CrystalDiskInfo condenses device-reported health information into a convenient summary, but that summary should be treated as a pointer to the underlying data. A Good status is not a guarantee against sudden failure, and a Caution status is not a complete diagnosis by itself.
If a warning appears, identify which field changed, protect important data, and consider whether the value is stable or increasing. For mechanical drives, reallocated or pending sectors can be meaningful. NVMe SSDs expose different fields such as percentage used, available spare, temperature and media/data integrity errors.
Common values you may see
| Value | How to interpret it |
|---|---|
| Reallocated Sector Count | Remapped sectors on media that became unreliable. A rising trend deserves attention. |
| Current Pending Sector Count | Unstable sectors awaiting later resolution. Secure data before stressing the drive. |
| Power-On Hours | Operating-time context; not a health verdict by itself. |
| Temperature | Compare idle and sustained-load behavior and use model-specific limits when available. |
| Percentage Used | An NVMe endurance indicator; it is not a precise countdown to sudden failure. |
What to do when something looks wrong
- Make sure important files exist somewhere else.
- Record the exact attribute and current value.
- Check whether the value changes over time.
- Confirm whether a USB bridge or enclosure could be hiding data.
- Use model-specific manufacturer diagnostics when appropriate.
What this guide does not do
This page does not provide CrystalDiskInfo, does not act as official product support and does not claim affiliation with the software developer. It explains commonly observed health information so you can read results more carefully.