CrystalDiskInfo Health Status Good Caution Bad Explained with SMART Values
CrystalDiskInfo gives your drive a simple verdict - Good, Caution or Bad - but the real story is in four SMART numbers below it. Learn which raw values actually matter, which ones you can ignore, and at exactly what point a drive must be replaced.
CrystalDiskInfo is the tool almost every technician opens first, and almost every user misreads. They see the big coloured health box - and nothing else. But two drives can both say Caution for completely different reasons, one urgent and one minor. The difference lives in the raw values of a handful of SMART attributes. Here is how to read them like a technician, and what each health status honestly demands from you.
👆 Example SMART panel — a real Caution drive pattern. Non-zero raw values on 05, C5 and C6 together mean the surface is failing.
What the Three Health Statuses Actually Mean
- Good (blue): every watched attribute is inside the maker's safe limits. It does not guarantee the drive can never fail suddenly — it means there is no visible wear or damage today
- Caution (yellow): at least one watched attribute has crossed the caution line. The drive still works, but something measurable is wrong. Caution is a backup alarm, not a decoration
- Bad (red): an attribute has crossed the maker's failure threshold. Treat the drive as already failed for planning purposes — rescue data now, replace it, and do not trust it with the only copy of anything
- For SSDs the status is usually shown as a percentage. Below roughly 10-20 percent remaining life, plan the replacement calmly instead of waiting for zero
The Four Numbers That Matter on a Hard Disk
Set CrystalDiskInfo to show raw values in decimal (Function → Advanced Feature → Raw Values → 10 [DEC]). Then watch these:
- 05 — Reallocated Sectors Count: sectors that went bad and were replaced by spares. Zero is healthy. Any number here means the surface has started failing, and if it keeps growing week to week, the drive is dying in slow motion
- C5 — Current Pending Sector Count: sectors that failed to read and are waiting for a verdict. These are the sectors behind your freezes and unreadable files. Non-zero C5 is the single most urgent number on the page
- C6 — Uncorrectable Sector Count: sectors that could not be read even after every retry and error-correction attempt. Non-zero C6 means data has already been lost somewhere
- C4 — Reallocation Event Count: how many times the drive has had to perform a rescue relocation. It should broadly track attribute 05
Numbers People Panic About That Are Usually Fine
Honesty cuts both ways. Some scary-looking values are normal:
- Temperature in the 30s and low 40s (Celsius) is normal for an HDD; sustained 50+ is worth improving airflow for
- Power-On Hours and Power-On Count show age and use, not damage. An old drive with clean 05/C5/C6 is healthier than a young drive with pending sectors
- Seek Error Rate and Read Error Rate show huge raw numbers on many Seagate drives by design — their raw fields pack two counters together. Judge those brands by 05, C5, C6 and the overall status instead
- One reallocated sector that appeared years ago and never grows again is a scar, not a death sentence — but the drive earns permanent monitoring, not blind trust
What to Do at Each Status — The Technician's Rule
- Good: carry on. Keep normal backups anyway — SMART cannot predict sudden electronic death
- Caution with C5 or C6 above zero: back up everything important today, starting with documents and photos. Then replace the drive. Do not run long stress tests, defragmentation or chkdsk repairs on it first — heavy work can finish a weak drive
- Caution only for temperature: fix cooling, re-check in a week
- Bad: data rescue first, replacement second, experiments never. If the data is critical and copying already fails or the drive clicks, stop and consider a professional recovery lab
How this health check fits into the full Windows-or-drive diagnosis is demonstrated in the video above.
🎥 Watch the Complete Process in the Video
Watch the complete health-check workflow - SMART status, event log evidence and the final Windows-or-drive decision - in the video.
▶️ Watch Full VideoCrystalDiskInfo says Caution but my PC works fine. Can I ignore it?
You can keep using the PC, but do not ignore the warning. Caution means the drive's own firmware has measured damage - usually pending or reallocated sectors. Drives can run for months in this state or fail this week; nobody can promise which. Back up your important data the same day, then replace the drive on your schedule instead of the drive's.
Why does my SSD show a percentage instead of Good or Caution?
SSD health is mainly about wear. Flash memory survives a limited number of writes, so makers report remaining life as a percentage based on total data written versus the rated endurance. 100 percent is new, and the drive usually keeps working below 10 percent - but that is the zone where replacement should already be planned, not postponed.
Can bad sectors be repaired so the health returns to Good?
A physically damaged sector cannot be healed. The drive can only hide it by substituting a spare sector, which is exactly what the reallocated count records - so the count stays as permanent evidence. Software claiming to restore Good health is editing the report, not the disk surface. Files already sitting on uncorrectable sectors are gone.