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Opteron Shanghai (8380) temperature offset

Posted: Tue Feb 23, 2016 1:18 pm
by Timoo
Hi,

I've recently set up a homeserver with an MSI K9ND Speedster2 mainboard and 2 Opteron 8380s.
When installing CoreTemp, I get readouts of between 1º and 13º (Everything here is in Celcius).
Obviously this cannot be, since operating temp of this CPU should be somewhere between 50º-60º.

So, I started looking for the correct offset.
20º doesn't do the trick: it would put operating temp at 25º.
Some sites suggest maxTemp = 77º.
Since CoreTemp tells me it is 115º, I took the difference as an offset, putting the CPU's at 40º-45º.
Not really satisfied, I kept on looking.

Then I ran on SpeedFan. Nice little proggy.
And maybe it contains some clue about the offset: it reads the Winbond W83627EHF sensor as -48º!
Then, when it uses the ADT7476 sensor, it reports temperatures of 13º-14º.
For me, this looks about right: 48º+13º = 61º
If Operating Temperature of the Shanghai's is between 55º and 77º, this would be about correct, in idle.

In SpeedFan I have [right now] CPU temps of 15º and 16º.
In CoreTemp I have, at the same time, temperatures of 4º and 9º.
This gives me a strange discrepancy, because if I would add the -48º, I end up with:
SpeedFan: 63º-64º
CoreTemp: 52º-57º

Not so much the difference between the programs is a problem, but the difference in CPU temps.
SpeedFan reports a 0º-1º difference between the CPU's (which makes sense)
CoreTemp reports a 5º difference (which is harder to believe, considering my setup and the fact that the 2nd CPU is used less than the 1st)

So, I started AIDA64, to use the system stability test.
This way I can run the CPU at 100%.
SpeedFan maxes out at around 27º (both CPUs)
CoreTemp runs at resp. 16º and 20º.
CPU temps 01.jpg
Since this CPU should have a max. temp of 77º, it would be safe to assume that the temp at this moment is between 75º and 77º, is it not?
This gives me an offset with CoreTemp of resp. 61º and 57º.
CPU temps 02.jpg
When I stop the stress test, it immediately drops to 17º in SpeedFan and 5º/10º in CoreTemp.

What is wisdom?
How to create a decent offset for CoreTemp?
Because SpeedFan is nice, but not what I want.
CoreTemp gives me the ability to monitor in a gadget, which is much more interesting.

Timo

ps. thanx for this little proggy!
It really gives me a chance to get my system stable *with old hardware, it is always guessing what's good and what's not...*

Re: Opteron Shanghai (8380) temperature offset

Posted: Wed Feb 24, 2016 11:05 am
by The Coolest
Interesting.
I suggest you read the following post by TomsHardware, as it sheds some light on how AMD's temperature detection works.
http://www.tomshardware.co.uk/faq/id-21 ... -apus.html
Although going with the values you see that would probably be wrong as well.
In any case you can configure Core Temp to use this method by going to Options --> Settings --> Advanced, check Display distance to TjMax.
I'm really not sure what I can say. AMD's CPUs seem to be a little 'problematic' in this regard, I don't think I can help you with this. I suggest to look what AIDA says about CPU temp.

Negative values in SpeedFan are usually displayed by inactive sensors, so 48 + 16 doesn't really work.