Which CPU temperature to believe?

[vfrex]

I'm preparing to give my previous computer to my brother to replace his ailing laptop. That said, the temperatures that this thing reaches are a bit worrysome to me. The processor is an AMD Barton 2800+. Ambient temp is 77F. CPU is idling around 100F with blower fan on high (~3700RPM). I am also running s2kdisconnect to further lower the CPU temperature at idle. Speedfan and Asus probe agree that the CPU temperature is 100F at idle.

I am now going to run an instance of CPU burn-in for 10 minutes. About 2-3 minutes in, Speedfan is reporting the CPU temperature to be 111 while Asus Probe is reporting it to be 122F.

At the end of 10 minutes, speedfan is reporting 115 while asus probe is reporting 127. The higher the temperature gets, the wider the gap. Still, isn't a 27F rise over idle a bit extreme?

To make things a bit more fair, I am going to disable s2kdisconnect, establish a new idle temperature, and then run a prime95 torture test for longer. The new idle result: Speedfan says 111, Asus Probe says 122.

Prime95 test for 5 minutes: Asus probe says 138, Speedfan says 122.
Prime95 test for 10 minutes: Probe says 140, speedfan says 124.

I can handle speedfan's output. 124F is tolerable under load. 140 is pushing it. 77F as an ambient temperature is probably close to as good as it will get. And I mean, this blower fan is spinning at 3700RPM. Could it be that Speedfan is reporting accurately and Asus Probe is off? I did read that some older asus motherboards report higher than actual temperatures. This is an A7V8X-X.

[Bio-Hazard]

First thing, NO MoBo reports temps correctly. Second, Asus as a norm reports temps on the low side, old Abit and DFI report them somewhat higher (same Bios programmer, he left Abit for DFi).
The reason you're getting 2 different readings is that speed fan is taking it's readings from a different sensor than Asus Probe. Try reconfiguring Speed Fan to use the same sensor as Probe.

[harry18]

hmm, i always found speedfan to be reallly inacurate, double check with a differnt programme i reacon

[vfrex]

Ok, motherboard monitor confirms Speedfan's reading. What else should I try?

[darkorb]

gwt everest, very good program

[Assassin]

Yeah no mobo sensor reason 100% accurate best thing to do would just average them out and thats around the temp your getting give or take some.

[Xero (1)ne]

didnt you learn anything in algerbra?
average them together:wink:

[DragonMaster]

Motherboards would cost a lot if they would have accurate readings for voltage and temperature. A multimeter that stays accurate with time will cost ~$150 or more, so do you think that mobos are accurate? The only way to test the real core temp is with a separate instrument that has it's own probe.

[vfrex]

Dragon, are you saying that we can't make conclusions based on the nominal temperatures provided? Or change in temperatures? Or both?

[DragonMaster]

Well, if the motherboard is telling 25°C, you can tell that it's at least around this temperature!