more accurate way to measure cpu temp

I always wanted to get a little 'closer to the truth' of what the cpu temp is. Most people use BIOS or software tools to measure the cpu temp which is read from either the internal diode or the sensor in the socket.

I decided to build my own temperature probe, a thermocouple, out of chromel and alumel wire which I spot welded together. This is a standard what is called 'Type K' thermocouple.



It's important when you make a thermocouple probe that you stay within the same material. So, all the connections have to be made out of the same material, too to prevent the creation of thermovoltages across the junctions of different materials which in turn would give you wrong temperature readings.

So, I took the thermocouple junction and glued it right next to the die with arctic thermal compund and fixed the wires on the cpu pcb with epoxy.



Then I cut a copper shim and put some insulation on the wires so they won't shorten out.



inside the case:



The wires go out at the back of my case to a type K thermocouple connector:



The first temperature comparison between BIOS reading and my multimeter..the difference is 4 celsius



So right now I'm running at

1.9V Vcore
38celsius idle
40celsius full load
(roomtemperature 28celsius)

nice one thats a good thing to do if u have an abit 1c7 max 3 and other mobos that read the temp funny

great work kepten, nice frabrication. i'd like to do the same but i don't trust myself with glueing and putting epoxy on the die.

Xplos!ve said:

nice one thats a good thing to do if u have an abit 1c7 max 3 and other mobos that read the temp funny

Click to expand...

For a P4 mainboard like the IC7 this method is less suited- you can only reach the heat spreader surface, not the actual core. You can't be sure then that any difference (-) is due to the location of the measurement or due to error.

Sweet. So your Abit NF7 Bios was actually reading 4°C "Too High"...
Did you do that comparison at full load or idle? If Idle, whats the difference at Full Load? Or if at Full Load, whats the difference at Idle?

the screen shown from the BIOS is from idle.

I'm using MBM to display the temperatures and most people agree that it displays the BIOS temperature.

So lets assume this is right then at full load MBM (or BIOS) displays a 5-6 celsius higher temperature than my multimeter/temp-probe.