Active SMART disk utility

SMART attribute meaning

ActiveSMART - is a well known S.M.A.R.T. utility for hard drives. It uses S.M.A.R.T. technology for hard drive diagnostic and monitoring.

Each S.M.A.R.T. attribute has its own value, meaning, and importance. Attributes are vendor- and drive-specific, but some of them are common for all manufacturers. Following is a list of attributes. Please note that it describes only part of all possible attributes, because different drive manufacturers use their own attribute dataset. Usually, the attribute raw value shows detailed information about attribute - amount of hours or amount of errors. Please find out more about S.M.A.R.T. terms in our Glossary

Note: This is only partial list of common S.M.A.R.T. attributes. If you want to learn more about attributes feel free to visit our S.M.A.R.T. attributes library at

Power On Hours Count This attribute shows drive aging, i.e. how long the drive is power on. The raw value of this attribute shows amount of hours of the power - on state.
Start/Stop Count Amount of drive's start/stop cycles.
Reallocated Sector Count Indicates amount of remapped sectors. If the sector became bad for some reason then the drive replaces it with a spare sector from a special spare area. The value of 100 means that no sectors were remapped. The raw value of this attribute shows exact amount of reallocated sectors.
Spin Up Time The raw value of this attribute indicates average time to spin up the drive spindle.
Spin Retry Count Count of retry of drive spindle spin start attempts. The raw value indicates amount of retries.
Power Cycle Count Count of disk power cycles. The raw value indicates amount of power cycles.
Raw Read Error Rate This value depends of read errors, and disk surface condition and indicates a read retries rate. Lower values indicate that there is a problem with either disk surface or read/write heads.
Write Error Count The raw value indicates amount of write errors.
Seek Error Rate Average rate of seek errors. This attribute indicates a state of head positioning mechanism. Lower values shows that there is a problem with head positioning.
Seek Time Performance Disk seek system performance.
Temperature If the drive contains a dedicated thermal sensor then this attribute shows a drive temperature. Active SMART supports drives with temperature sensors.
Throughput Performance Overall throughput performance of the drive.
Off-line Scan Uncorrectable Sector Count Amount of error sectors detected during the last off-line scan.
Current Pending Sector Count Amount of pending sectors. If the sector issues and error during read or write the drive marks it as pending for a certain time before replacing this error sector with a spare one.
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