CrystalDiskInfo is a free Windows utility for checking the condition and operating information of hard drives and SSDs. It reads the drive’s self-monitoring data, displays a health assessment and temperature, and can watch for changes while running in the notification area. It works with internal storage and supported external drives, including SATA and NVMe devices.
How CrystalDiskInfo assesses drive health
The main window brings together a simple health label and the attributes behind it. The S.M.A.R.T. table identifies each attribute and shows its current value, worst recorded value, critical threshold and raw data. Raw values can be displayed in different numerical formats.
For hard drives, CrystalDiskInfo uses reallocated sectors, pending sectors and uncorrectable sectors when deciding whether to show Caution. These represent different conditions: sectors already replaced with spares, sectors awaiting a decision about replacement, and sectors that could not be corrected. The caution thresholds for these attributes are adjustable in the health settings.
SSD health assessment depends on the attributes available from its controller, including remaining-life indicators on supported models. CrystalDiskInfo presents the assessment as Good, Caution, Bad or Unknown, with a corresponding color.
Drive details
Selecting a disk also shows its model, capacity, firmware and serial number. Drive letters help connect a physical device with the volumes visible in Windows, while the interface and transfer-mode fields identify its connection and show both the current and supported modes. Power-on hours and power-on count provide context about the drive’s recorded use.
The available details vary with the hardware. A hard drive can report its rotation rate, while a supported SSD is identified as non-rotating storage. The supported-features line indicates capabilities such as S.M.A.R.T., TRIM and power management. CrystalDiskInfo can hide serial numbers when the displayed information needs to be shared.
Device access also depends on the controller or external enclosure. Many USB hard drives and SSDs are supported, but multi-drive enclosures and most RAID controllers have limits. AMD StoreMI is unsupported, so an attached disk is not necessarily accessible simply because Windows can use its storage.
Disk monitoring
CrystalDiskInfo can refresh readings at a chosen interval and lets users choose which disks participate in automatic refresh. A manual refresh requests current information, while a rescan looks again for disks. Resident mode keeps the utility in the notification area, where temperature icons provide a continuing view without leaving the main window open.
Graphs plot S.M.A.R.T. information over time, allowing changes in an attribute to be examined across successive readings. The graph window offers controls for the maximum number of plotted points, legend position and date-and-time presentation.
Health alerts
Temperature and health alarms bring changes to attention through the tray display and an optional alert sound. Email notifications extend this to a configured mail recipient. Their messages identify the computer and disk and describe the event, such as a change in health status or a sector count. Mail settings include server connection details and a test-message function.
CrystalDiskInfo can also write events to the Windows Application log. Warnings cover deteriorating health, relevant sector-count changes, high temperature and drive-life alarms; informational entries record supported recovery events. For a separate snapshot, the Copy command places selected disk information on the clipboard. Command-line copy options can write that information to a text file, with an option to exit afterward.
AAM/APM controls
On drives that expose the corresponding features, CrystalDiskInfo provides Automatic Acoustic Management and Advanced Power Management controls. Acoustic settings select a level between lower operating noise and maximum performance. Power settings select a management level, including ranges that allow standby and ranges that keep standby disabled. An automatic-application option reapplies these settings at startup or when a new disk is detected.
