Can I trust SMART readings?

albert · Post by **albert** » Sat Aug 04, 2007 2:12 am

I've just built a new system (V quiet, quite happy) but one of my drives is reporting very hot.

It's a samsung hd080HJ. Yesterday it hit 57! (Ambient temp probably around 25).

However, I checked the temp immediately after starting the PC this morning and this drive was reading 30 - at an ambient temperature of 22. The other drive in the machine reported a more plausible 22.

As the system warms up, there seems to be a fairly consistent 7-8 degree difference between the 2. I'm inclined to think there must be some sort of error in the Samsung's temp monitor and ignore the high reading. It feels quite hot to the touch, but not so bad you can't hold onto it.

Second opinions please?

Das_Saunamies · Post by **Das_Saunamies** » Sat Aug 04, 2007 3:46 am

SMART has been reliable and consistent on all of my HDDs, all of which have been Seagates, Maxtors and WDs.

Some drives just get terribly hot, and the differences by model in measuring explain individual differences. Those temperatures are nothing out of the ordinary, even the high one, assuming you have no active cooling for the HDDs. You can try and reproduce it with some heavy-duty defragmenting or continued drive use, see how high it can climb. Temperatures at start won't match temperatures after a long stretch of use.

Also, could you describe your setup for case, airflow and HDD rack?

bkh · Post by **bkh** » Sat Aug 04, 2007 7:09 am

Try to get some air blowing on that hot disk. Any quiet fan at very slow speed should be plenty to bring that disk temp down.

albert · Post by **albert** » Sat Aug 04, 2007 1:40 pm

The case is home made - MDF. However the basic layout is based on a P180 so I have the 2 drives suspended at the front of a bottom compartment with the PSU drawing air over them.

However, the PSU is S12-380 - new revision. The stock fan was a bit of a disaster (based on the recommended list here, I didn't peruse the forum carefully enough first). I've replaced the fan with a Scythe one I had lying around and it's spinning very slowly, so airflow is minimal.

Obviously there's the option to add another fan into the lower chamber or to stop using the S12's fan controller and set the fan in there to spin faster. I haven't decided yet which option is best - or even if either is necessary.

Das_Saunamies · Post by **Das_Saunamies** » Sat Aug 04, 2007 2:03 pm

Well, as long as the temperatures are below manufacturer maximums and stable at what they are, you've got no problem. It's been deduced that changes in temperature are more of a problem than a constantly high one, as long as it's below specifications.

A wooden case with an indirect exhaust only for the HDDs? No wonder they're hot. So yeah, trust your SMART, the readings will be as reliable as they get.

Chang · Post by **Chang** » Mon Aug 06, 2007 10:51 am

Assuming they're the same make and model of drive, one easy check would be to swap their positions. Even if they're different, I suspect you'll see enough of a large swing to confirm that you could use some active cooling on the "hot" drive.

albert · Post by **albert** » Mon Aug 06, 2007 1:20 pm

Well I've put in some active cooling and both drives are now running at an acceptable temp. I'm still deeply suspicious of the readings on the high one though. I just can't see how it could hit 30 degrees from cold in the 30 seconds it takes to boot the system.

I'll try swapping the pair at some point soon and let you know if it makes any difference.