Temperature reading accuracy

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How accurate is the cpu temperature reading on a VIA mobo?

 

[hwstock]

<< How accurate is the cpu temperature reading on a VIA mobo? >>


Yell us the board and CPU in use, and how you are reading the temperature.

If you have an asus a7v-266a with an Athlon XP, and you have the board set up to use the on-chip temperature sensor, and the software that reads the temp is decent... then the temperature is probably very accurate.

 

[Link]

What I meant to ask in the first place was that unlike P4 mobo, Athlon mobo measures cpu temp from the exterior of the cpu whereas P4 mobo gets the reading from the cpu core.
So does that reading represent the actual cpu temp?

 

[hwstock]

<< What I meant to ask in the first place was that unlike P4 mobo, Athlon mobo measures cpu temp from the exterior of the cpu whereas P4 mobo gets the reading from the cpu core.
So does that reading represent the actual cpu temp? >>



First, some Athlon Mobos CAN read the die (true CPU) temperature -- provided they have an XP and are properly jumpered -- just as P4 motherboards do.

Most, though, read the temperature from a sensor below the CPU, in the center of the CPU socket. This temperature is extrapolated to the presumed temperature at the die, using an empirical relationship (the AMD site has pdf documents that describe the process). One problem: the relationship is not the same for ceramic chips (older Athlons) as for the new organic carrier XP chips.

Check for posts by MikeWarrior2.

 

[Mikewarrior2]

Well, even if the AMD manufacturers "extrapolate" and "manipulate" socket-thermistor readings to try to match die temps, they are failing:

Void Your Warranty review comparing Socket-Thermistor, Side Thermistor, Direct Under Thermistor.

This test was done with an asus A7V, one of the "higher" reading AMD motherboards. Even then, if you take the amd 24228.pdf, regarding ceramic PCB cpu's and "temperature" measurements to extrapolate die temp, you get this:

Tceramic = 63C
Tambient = ~25C (e-mailed the question to the author)

Tdie = (1.209 *(63-25)-1.3778) + 25 = ~69.5C

So, even the supposedly "high" reading asus mb's read too low, you're talking 53C MBM reading and 69.5C "Die" temperature, with a Ceramic PCB T-bird


Mike