CPU temp vs Core temp

[996GT2]

I've noticed that Speedfan displays both, with the Core temp being the lower of the two. Which is a more accurate indicator of actual CPU temps?

 

[BlahBlahYouToo]

what cpu?
use realtemp for intel 45nm cpu's.

 

[996GT2]

CPU is Athlon X2 65nm Brisbane G2 stepping

I'm using CoreTemp and Speedfan right now. The "Core" temps from both programs match, but Speedfan's "CPU" temperature is usualy 5-15C higher depending on load.