Crystal Disk Guide

Understand what your drive is telling you.

Practical guides for reading HDD, SSD and NVMe health information in CrystalDiskInfo.

Independent knowledge base. Not affiliated with Crystal Dew World or the CrystalDiskInfo project.

Start here

Three common starting points

Understand Good, Caution and Bad drive health indicators.

Learn what important HDD and SSD attributes mean.

Interpret endurance, Percentage Used, spare capacity and error indicators.

Warning status

Protect data first, then read the value that triggered the warning.

Topics

Sector warnings, reallocation and pending sectors.

Endurance, remaining life and spare capacity.

Critical Warning, Percentage Used and error logs.

Columns, raw values and vendor differences.

Alert thresholds, specifications and throttling.

Caution, C7 and external-drive visibility.

Popular

A field-by-field guide to the main window so you can understand what CrystalDiskInfo is reporting.

A practical, conservative response plan for CrystalDiskInfo Caution and Bad health status.

Understand the columns in the S.M.A.R.T. table and why raw numbers must be interpreted conservatively.

What the common HDD sector-warning attributes mean and why the trend matters.

SSD health percentages usually describe consumed endurance, not a precise remaining-life calendar.

A practical guide to common NVMe health log fields shown by CrystalDiskInfo.