Quick answer
SMART data shows you whether your disk has hardware problems that can lead to data loss. You can perform the check on Windows using tools like CrystalDiskInfo or a PowerShell command, on macOS via Disk Utility, and on Linux via smartctl. Catching a problem early lets you save your data and replace the disk before it fails.
How to recognize the problem
- The computer is slow when reading and writing files
- Unusual noises come from the disk (clicking, humming)
- Errors occasionally appear when opening files
- System events report disk errors
- The disk gets hotter than usual
Most common causes
Worn mechanical parts (HDD)
In hard drives, wear on bearings and heads can cause read and write errors. SMART attributes like reallocated sector count and read errors indicate physical degradation.
Power supply issues
Unstable voltage can lead to disk operation errors and incorrect SMART values. Check the cables and power supply if errors recur.
Faulty SATA or USB cable
A bad cable can cause connection drops and false SMART errors. Replace the cable before concluding about disk health.
Power surges or impacts
Physical impacts can damage the disk, especially HDDs. SMART attributes will record an increased number of errors.
Firmware or drivers
Rarely, firmware updates or incompatible drivers can display inaccurate SMART data. Check that drivers are up to date.
Step-by-step fix
- 1
Install a tool to read SMART data
Download the free tool CrystalDiskInfo from the official website. Install it or run the portable version. Alternatively, you can use the PowerShell command
Get-PhysicalDiskfor basic information. - 2
Run the tool and read the SMART status
Launch CrystalDiskInfo. In the main window you will see a list of disks and their status (e.g., Good or Caution). Click on the disk you want to check.
- 3
Review key SMART attributes
Pay attention to attributes such as Reallocated Sectors Count, Current Pending Sector Count, Uncorrectable Sector Count, and Power-On Hours. For Reallocated Sectors Count, Current Pending Sector Count, and Uncorrectable Sector Count, values greater than zero or increasing can indicate a problem. Power-On Hours shows the age of the disk.
- 4
Check temperature and runtime
HDD temperature should not exceed around 50°C, while for SSD check the manufacturer's specifications. Power-On Hours shows how long the disk has been running; older disks are more prone to failure.
- 5
Use PowerShell for a quick check
Open PowerShell as administrator and run
Get-PhysicalDisk | Select-Object FriendlyName, HealthStatus, OperationalStatus. This gives basic status but not all SMART attributes. - 6
On macOS, use Disk Utility
Open
Disk Utility(Disk Utility > View > Show All Devices). Select the disk and click Info. SMART status will be displayed if available. - 7
On Linux, use smartctl
Install the
smartmontoolspackage and runsudo smartctl -a /dev/sda(replacesdawith the appropriate disk). This tool displays all SMART attributes and status. - 8
Interpret the results and decide
If the SMART status is Caution or Bad, immediately back up your data. If certain attributes are critical (e.g., reallocated sectors), plan to replace the disk.
What if SMART is not available or the data is unclear
Some older disks or USB enclosures do not support SMART. In that case, use manufacturer tools (e.g., SeaTools, Western Digital Dashboard) or check disk integrity with the chkdsk command without the /f option (check only) in Windows. If you suspect a failure but SMART is clean, monitor system behavior: frequent freezes, read errors, or unusual noises may indicate the disk should be replaced. Make regular backups, because SMART is not perfect and does not predict all failures.
How to prevent it
- Regularly back up important data
- Keep the disk at operating temperature and ensure ventilation
- Use quality power supply and cables
- Check SMART status periodically (e.g., once a month)
When to call a professional
If you are unsure how to interpret SMART attributes or if the disk shows signs of failure, consult an IT expert. They can perform detailed diagnostics and suggest the best solution for replacement or data recovery.
IT infrastructure maintenance · Servers, networks, backup, security and helpdeskFAQ
Can SMART predict disk failure?
SMART can indicate an impending failure, but it is not 100% reliable. Some disks fail without prior SMART warnings, so regular backups are the best protection.
How often should I check SMART data?
It is recommended to check once a month or after noticing symptoms. If you handle critical data, check more often.
What does the "Caution" status in CrystalDiskInfo mean?
The "Caution" status indicates that some SMART attributes have reached threshold values. This does not necessarily mean immediate failure, but it requires an urgent backup and monitoring.