Where does a temperature probe have to be placed on a P4?

I've just about put my probe everywhere, near my cpu, on my heatsink (SLK-900U). Nothing seems to give me accurate readouts. I think it's my 92cm Tornado on top of it (3K rpm), anywhere I put the probe and it's exposed to gushing air. Lord, been at it all day I have an Abit IC7-G so there's no getting real temps there with the temp calculation issue and all. Anyone have any good experiences with a temperature probe spot on a P4?

Maybe you could put a piece of electical tape over it... that MIGHT conduct heat badly enough to where it wont effect temp reading that much.

But at anyrate at least you know it's (the heatsink) working

underneath the cpu, between it and the mobo...

stan03 said:

underneath the cpu, between it and the mobo...

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You can stick it through all the pins?

Your P4 is much like a refrigerator or an oven. Where can you place a probe on the outside to get an accurate temperature of the inside? You can't. Any diode inside the chip will be far more accurate than a thermal probe placed outside the chip. For more info, read Why Many Thermal Measurements Are Not Valid.

Here's an interesting heatsink round up that illustrates the point.

Somehow or other, but the main conclusion is this: for hardcore overclocking, the readings of external thermal sensor are absolutely useless since they don't reflect the factual processor core temperatures.

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You may find Temperature Sensing Technologies a good read too.

Now that we have figured out the best place to read the temperature is inside the CPU die, another problem pops up. With PII and PIII CPUs, the sensor was in the hottest part of the chip. Here's what Intel has to say about PIII diode placement. With both P4s and Athlons the diode is no longer in the hottest part of the chip. A little more reading from Intel on the subject. We have the same problems measuring temperatures inside the core when the diode is not in the hot spot as those outlined in Why Many Thermal Measurements Are Not Valid.

The only accurate CPU temperature measurements are from PII or PIII internal diodes provided you have a motherboard that can read the internal diode. There is no way for the end user to get an accurate temperature reading from an AMD CPU or a P4.

Furthermore, if you consider the last link from Intel, your P4 is most likely throttling more often than you may realize.

try to put in on the bottom of the heatsink as close as can get it without touching the cpu

mbm is readin 42C and my lian li temp display is reading 86.3F/30.1C
so if the abit boards are reading off by 10 at least, i'm getting a close reading