Hard drive temperatures

[BespinReactorShaft]

I've been using HDTune to get details on my hard drives. Currently it shows ~40 deg.C. How can it determine this temperature? Are temperature sensors built into most/all HDDs today?

Btw, what would be "safe" operating temps for HDDs?

 

[lobadobadingdong]

dunno about general saftey temps, mine usually runs at around 27C according to speedfan.

 

[BespinReactorShaft]

How about HDD temp sensors? I'm still wondering if this program is pulling a fast one...