Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

I had an argue with a colleague about :

  • "How do software programs (i.e. hwmonitor) determine the temperature of the hard drive?"

enter image description here

I said that there must be a thermometer inside the HDD and the data (via SMART) is passed as regular info to the soft which wants that info .

He said : "No. There is no thermometer inside the HDD. You have to plug it as another hardware on your HDD. All the software uses statistics about heat from the RPM info"

  • How do software programs like hwmonitor, determine the temperature of the HDD?
share|improve this question
Your colleague is completely clueless and foolish. –  barlop Apr 28 '13 at 22:44

3 Answers 3

up vote 32 down vote accepted

The hard drive has a temperature sensor (or multiple temperature sensors - they might be used for internal control, self-test etc...) inside, and this data is passed through SMART (in fact, this is a standardized SMART parameter).

share|improve this answer
Aye. OP could have found by just reading http://en.wikipedia.org/wiki/S.M.A.R.T., scrolling to parameter 190 ans searchinf for the word temperature. (E.g. open page, <kbd>Control</kbd>-<kbd>F</kbd>, temperature <kbd>Enter</kbd>). –  Hennes Apr 28 '13 at 20:00
@Hennes I assumed it relates to SMART. wasn't so sure. and hence - did not look it under SMART category. –  Royi Namir Apr 28 '13 at 20:06
Now you have two links to show your colleague though. ;-) –  Hennes Apr 28 '13 at 20:07
But by posting it on SO many of gets to be entertained, so it's not a waste. –  crdx May 3 '13 at 17:53

No, the temperature monitor is embedded into the HDD. It's a more recent addition and you will only see it with some of the newer SCSI disks. Anything older than a few years won't have the sensors.

It's actually a part of the S.M.A.R.T. suite that reports around 30 attributes. (http://www.hdsentinel.com/smart/index.php)

The software just pulls it from the hardware. You won the argument.

share|improve this answer
I don't understand. SMART has been for years now. are you telling me that only the new drives has sensors ? I have a 5 years old drive which I can tell its temperature....please explain. –  Royi Namir Apr 28 '13 at 20:08
It's an infrared thermometer. It's integrated in the hard drive. I used to have to replace them all the time when they used to have a high failure rate. They are pretty good now. Edit: Anything supporting SMART should have the thermometer integrated. 5 years old is not that bad. I'm talking about 10-15 years old. –  Will.Beninger Apr 28 '13 at 20:08
oh ok :-)....... –  Royi Namir Apr 28 '13 at 20:14
Consumer hard drives started including temperature sensors in 2008. Before that, PCs typically had no hard drive temperature sensors and Macs typically had a sensor bonded to the outside of the drive. Modern drives have a sensor bonded to the inside of the drive casing. Last I checked, most hard drives used thermistors because there was no device already bonded to the inside of the case and a thermistor is cheap if used alone. SSDs typically use silicon bandgap temperature sensors integrated into the controller, cheap because no additional device is needed. –  David Schwartz Apr 28 '13 at 20:31

all the software uses statistics about heat from the RPM info"

Hard disk drives spin at a constant rate (usually 5400 RPM, 7200 RPM, 10000 RPM, or 15000 RPM). So the statistics on RPM info will probably be of little value for determining temperature.

share|improve this answer
Obviously the higher the RPM the cooler the drive is, since the faster-spinning platters fling the heat off of the surface with much greater force than the slower platters. /s –  Justin ᚅᚔᚈᚄᚒᚔ Apr 29 '13 at 15:51
@Justinᚅᚔᚈᚄᚒᚔ I would upvote that, but I'm afraid that future visitors might think you're serious. :) –  Moshe Katz Apr 29 '13 at 19:36

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.