Hwinfo64 gpu temp measurement help

Hi, I have been using hwinfo64, gpu-z, and hwmonitor to monitor my temps for my gpu, amd 6990m (and also for cpu though as secondary). I usually measure during a 30-45 minute gaming period using all three or atleast two programs (with hwinfo64 I enable "Compal EC" as I heard it would be more accurate). The games are generally the latest ones like max payne 3 or batman arkham city with high details and dx11 on.

What I would like to know is what in hwinfo64 is more reliable/accurate for gpu temp measurements, the measurement under "Compal EC" or the measurment under graphics card section which mentions several temp monitors on the card, in particular "GPU Thermal Diode"?

What I have seen is the temps under "GPU Thermal Diode" is similar to what I see on gpu-z and hwmonitor for gpu temp (around 80-81 Celsius), but compal ec is usually 8-9 degrees less than this (71-72 celsius), so I would really like to know what is more accurate, as there is a large difference in temps from different softwares. Any help would be appreciated, thanks.

NOTE: I have latest version for all softwares, and have had zero glitches with hwinfo64 so far.

 

Sad part of this is it must actually work or they wouldn't do it. Action now! I love it!

On topic.. I think the diode temp should be accurate. Its on die. The other sensor is external, makes sense it would be lower.