A friend asked about sleeping his drives “to extend their life.”

Personally, my laptop uses SSDs, so drive energy is minimized. I have a tendency to leave it on all the time, popping the top when I need it, and closing it when I don’t. Therefore, sleep on that machine is in “manual mode.”

My main computer is powered off at night and restarted in the morning. In that, sleep is set to “never”.

I have an external SATA raid box, which powers up and down automatically with the machine. I also have a FirmTek external sata that I use as needed for some 20-ish removable drives. Obviously, those drives spin up as I insert them and down when I remove them.

My own take is that spinning up and powering down, (that is, going from cold to hot to cold) is more wear and tear (in terms of time) than leaving a drive running at a constant temperature.

How much more?  I have concluded that it’s about 25-30% of the expected life. That is, if you hot/cold/hot once a day (as I do powering off at night) a drive that would last about 4 years running full time will last about 4 years.

HUH?  Well, remember that in my 24 hour day, that drive is off about 8 hours (at night): it’s total ON time is about 75% of the “always on” drive.

This was once, years ago, confirmed with I spoke to a drive engineer about this very question directly. She said “Yes, and that’s why we can put a length on a warranty: it will be about the same whether the drive is running all the time, or turned on and off.”

Where does the wear occur?  In the motor (it strains during spin up) and the drive bearings (microscopic cracks due to hot/cold expansion of the material.)

Upshot?  Pretty much like L-ion batteries. Don’t worry about it: the difference you’ll make with all that psychic energy isn’t really worth the mental strain.

YMMV

Tracy