I'm looking at my i5 750's (stock speed and voltage) temperatures under load (a game) using RealTemp right now. Core 0 is around 50, Core 1 around 38, the others are in the low to mid 40s. I also noticed in CoreTemp that Core 0 is under a lot more load than the others.
Is this temperature variation just due to the game making use of some cores more than others?
The temp variation is probably due to the game just using one core. I think each temp monitor on the cpu could be off by a slight amount(maybe core 0 is +3 to its temp while core 1 is -3 to its temp). What game is it btw? If it's multi-threaded then it should keep the cores close on temps.
It's Just Cause 2. I did check the load while it was running and it was only really using Core 0, which was the hot one. I just ran prime95 and pushed the load on all cores to 100%...the temps evened out just fine.