Lone Ranger wrote:
I use the Samsung 160GB disk and have out an external temp probe on it. I find tha the SMART temp value is indeed different. You would expect this as my probe is on the base of the spindle support part of the drive and I have no idea where the SMART sensor is.
You mean under the motor, yes? A picture would be nice...
What type of thermistor do You use? Flat one, or some other kind?
The only reference to measuring drive temperatures w/ external sensor which I've seen was on Seagate 15K.3's datasheet. The "right" spot to measure is above the connectors, in the middle of the "chassis" of the drive (the metal part).
Lone Ranger wrote:
At low temps of 14C I get a difference in readings of about 4 degrees with the proble saying 18C and Samsung sating 14C. As the drive warms up more and more and the heat districution becomes more even then the two start to match although the probe is always a bit hotter.
Right now DTEMP is giving me 25C for the Samsung but the probe says 26.0.
Today as I booted my computer (been off nearly two days), with ambient 20°C, I measured the SMART temp of 17°C as I got to the desktop. The drive's temp rose to 19°C, stayed there for 3-4 mins, then dropped to 15°C for one minute (notice that most software measures drive temps only every minute) and then rose to 17°C (2-3 min), and then back to 19°C (one min).
Then it dropped to 18°C, was there for 2-3 mins, then jumped to 25°C! After that the temp rises two degrees at a time, and after 90 mins, temp is now 31°C. As I've mentioned earlier, the drive shows only odd values, except before the jump. Internal calibration perhaps?
I've turned the computer off few times to remove/attach a HD (I have a Kingwin rack), which takes like 30 seconds. When I boot back to Windows, the drive's temp is much higher than it was when I shut down. I'd say at least 4-6 degrees, but I can't remember exactly. After a while (say, 15-30 mins) the temp gradually drops to the level before the shut down. Rebooting doesn't produce this effect. I think that the drive calibrates the sensor if the drive is unpowered.
BTW, SpeedFan 4.09 has a graph feature, which is quite nice for following temps over time.