I’m not good at case-modding, and I cannot judge at all whether a cooling system is a good one or not. So I have to totally trust in the engineering power which Microsoft has invested into the Xbox 360 cooling system.

Still, my Xbox #9 had a problem, even I could see that.

I’ve removed the GPU heatsink, and removed the (evil? Probably not really.) thermal foil (I couldn’t see any damage/misalignment on it, though.), and applied some little bit of arctic silver 5 instead (after cleaning the heatsink).

so this looks already MUCH better (notice the smaller difference between the 2nd (GPU) and 3rd (EDRAM) temperature!).

It now matches the cooling performance of the other 9 boxes. (That also means that the arctic silver is as good as the original thermal foil - UNLESS something is wrong with it.)

What worries me more is that this issue didn’t seem to be caused by a miscalibrated or defective sensor - it seems that my change really changed the temperature. That also means that it was incorrect before, possibly overheating.