How bad is Spin-Up Time in HDD?

I have a newly brought laptop and it has WD Black 7200 RPM HDD. And yesterday I took a screenshot from CystalDiskInfo and I kept it and today I just opened CystalDiskInfo and compared the values with that old screenshot and I see the spin-up time value has changed. 1 day ago the spin-up time was

Attribute Name | Current | Worst | Threshold
spin-up time   |    186  |   181 |    21

But today it is

Attribute Name | Current | Worst | Threshold
spin-up time   |    184  |   181 |    21

Why is the Current value is decreasing? And even this is a new HDD brought a month ago. So I would like to know how serious is this problem and is anything wrong with the values shows in the CrystalDiskInfo. Anybody can help me? Thanks in advance.

Solution 1:

The SMART S.M.A.R.T. Attribute: Spin-Up Time is defined as:

Spin-Up Time S.M.A.R.T. parameter indicates an average time (in milliseconds or seconds) of spindle spinup (from zero RPM (Revolutions Per Minute) to fully operational).

This parameter is considered informational by the most hardware vendors. Although degradation of this parameter can be an indicator of drive aging and/or potential electromechanical problems, it does not directly indicate imminent drive failure.

Spin up time may depend on many parameters, such as the ambient temperature of the drive. This is why this parameter shows an average value, rather than an exact one.

You should only be worried if this value starts to degrade, indicating an aging disk. As in your case the time 184 is less than the average 186, everything is fine.