If the health value is low, the remaining lifetime display will remain unchanged for many days, even if the power on time value increases. The total remaining lifetime is 1225 x 0.7 x 0.7 = 600 days and 6 hours.Īs you can see, the health value drastically determines the estimated remaining lifetime of the hard disk. Of course in an ideal situation this value will not decrease even after hundreds of days.įor example: the hard disk is working for 600 days (600 x 24 hours) and its temperature was not too hot (there were no days with too high average temperature) and the health is 70%. Note: Hard Disk Sentinel displays 1000 days as maximum value for estimated remaining lifetime. The result is multiplied by the square of the health value of the disk. If the maximum (peak) temperature was high, it is not so critical but if the average temperature was too high (it means the temperature was high for longer time) the result is reduced drastically.

The result is decreased according the number of days when the temperature was too high. The elapsed power on time decreases this value. This is equal to 1825 days in 24/7 mode or 43800 hours. If the 'Analyse data field' option is selected as condition calculation method on the advanced options page, the remaining lifetime is calculated by the following method:īy default, the total expected lifetime of a hard disk in perfect condition is defined as 5 years (running every day and night on all days). Estimated remaining lifetime Analyse data field Note: the power on time display may not be correct on some models. For example, a two years old hard disk which is used 12 hours every day will show the same 'power on time' as a one year old hard disk which is used in 24/7 mode (like a 3 years old hard disk working 8 hours every day). Idle time (when there was no read or write operation) also increases this value but standby time does not increase this time. The value displayed next to the Power on time indicates the total time the drive was running (powered). The received reports help in further development and it is possible that in a later version the exact power on time count will be displayed from the first time (without the need of the measurement). When the measurement completed, it is recommended to send a test report. If the displayed value seems to be incorrect (too low or high), the 'Repeat Test' button can be used. This measurement has no effect on the performance of the hard disk or the computer.Īfter the measurement (or if it is not required) the exact, accurate power on time value is displayed (with black color) and the 'estimated value' text is not displayed. After successful measure, the unit is saved and it will be used automatically later. If the user closes the application during the test, it will be automatically restarted on the next launch of Hard Disk Sentinel until it can determine the unit of time used on all hard disks. During this test, an estimated power on time value is displayed (with grey color) and it may not be accurate. It checks the elapsed time between two consecutive increases of the raw value of this attribute. Different units are also possible and two hard disks from the same manufacturer may not have same time units.Īfter installation, Hard Disk Sentinel starts examining this attribute. It can be hours (the value is increased once per every hour), minutes or half-minutes. The unit of the time depends on the manufacturer. The raw value of this attribute is constantly increasing when the hard disk is under power (running, but not neccessarily performing a read or write operation). This value is supported by most modern IDE and S-ATA hard disks. Hard disk power on time can be determined by examining the #9 'Power on time count' S.M.A.R.T.

Disk graph calc