Which temp monitor is correct ?

I have been using a program called PC Probe II and it is an Asus program that works with only those boards. The program says that my idle cpu temp is 30c and my mobo is 35c but when I go into the bios and let the computer idle at the hardware monitor screen the bios says the cpu is 35c and the modo is 30c. Which one should I go by?

 

You could always try the patented Highland3r touch test
http://www.drunken-student.co.uk/touch/

 

Core Temp http://www.alcpu.com/CoreTemp/

or

Speedfan http://www.almico.com/speedfan.php

 

The BIOS is the correct reading, always go by that

 

I always found BIOS readings to be out by a few degrees compared to external heat probe readings.

 

I agree with topdog555. I use both coretemp and speedfan. Both read the same and both seem reasonable. I have heard that ASUS PC Probe sucks and was told to disregard it if I ever got an ASUS board.

 

I also agree with Core Temp and SpeedFan.

But CPU CooL is a very good monitoring program (handles mobo temps, HDD's etc too). It's not free though - but it's well worth the small fee, for what it offers IMHO.
Real Temp (Intel only) is a relatively new program (just 120kb in size!), is worth a try as well?

 

Wouldn't the BIOS be reading the core temperature because it uses the in CPU thermal sensor whereas the external probe would be reading the heatsink temperature and does not use the in CPU thermal sensor?

The most accurate reading of the CPU temperature would be done by the in CPU thermal sensor, sometimes called the on die sensor.

This would mean the BIOS temperature reading would always be different to any external temperature reading, the internal would always show a higher temperature and be more accurate.

The temperature reading on the heatsink would be less accurate because different heatsinks have different amounts of thermal mass and also the thermal sensor would be at different distances from the CPU depending on size and design of the heatsink.

I would use the BIOS temperature reading for an accurate measurement of CPU core temperature and only use the external reading as a guide to the effectiveness of the heatsink if I was to use an external thermal sensor.

Software that shows the temperature while windows is running would use the same thermal sensor that the BIOS uses, so as long as the software is accurately reading and reporting the temperature I would go by that when windows is running.