Which Temp reading should i believe Bios Or Motherboard Monitor?

[stevefromuk]

Hi
I have a amd athlon xp 2400+
and the bios is reporting the temp at 36-37c at start and about 45c- 47c after a few hours .
But
I have installed Motherboard Monitor 5 and that is telling me the temp is 64c even when i first switch on in a morning,and si soft sandra says the same (But this is also reporting the board temp at being 124c ).
The case has too fans with good air flow and the inside of the case seems ok but these readings have got me worried.
This is the first pc i have built and is only 2 month old.
Any help would be great
My pc specs

Amd ahtlonXp 2400+(with amd's heatsink)
Pc Chips M848alu Motherboard
256mb pc 2700 ddr ram
400w psu
40gb h/d

[MaxVal]

I would be inclined to believe the BIOS reading.
I have tried this monitoring program with limited success.
If you know the MB manufacturer, you might try visiting their website as there may well be a compatible monitoring program available for download.

Most of the time boards use a thermistor for the BIOS temperature reading. This is somewhat inaccurate since the thermistor is on the underside of the chip, not the core.

Motherboard Monitor tries to use the chip's temperature sensor instead, thus will be more accurate. There is a list of which sensors you should use for just about every motherboard on the Motherboard Monitor site. That might help a bit.

[ShawnD1]

I would say trust motherboard monitor. When you're in the bios, your CPU usage is 0%. When you're in Windows running distributed computing programs, you're using 100%. If you turn those DC programs off and let the CPU usage go down to 0, motherboard monitor will give you the same temp as the bios.