Ahh, the age-old which-temps-do-I-trust issue.
Having owned a couple of Asus motherboards now, I'm comfortable with this being a relative thing. I did, however get real curious about my temps when I put this new WC system together.
Besides curiosity, I thought having MBM running with ShutDownNow set for a reasonable max temp would probably be a smart thing.
So as it stands: ambient is generally 25-26C. Bios gives the CPU temp at about 30-31.5C, with the MB at a steady 28C.
MBM gives (looking at it now, with ambient at 26.3C) MB: 29C, CPU: 35C.
These are, of course, idle temps. I've run CPU Stability Test and UT2003, and the load temp usually doesn't rise over 44C.
What impresses me more, though, is that as soon as the load is off, the temps drop back down in a matter of seconds. My air system never did that.
So which is an accurate temp? The bios? MBM? Neither?
I'm trying not to care. I'm happier with these numbers than I have been with any of my air-cooled systems, and I feel that a SDN setting of 55-60C (depending on my paranoia) should protect my system.
I almost forgot: I'm breaking in the 2.66 at 3.0 right now, and have upped the core voltage a notch. A lot of people try to compare temps without taking into account the biggest factors: ambient temp, and OC voltage.