Heat Question

[demi]

hi,
I recently became interested in the question of which processor generates how much heat. My questions are:
1) Considering the processors M780(2.26GHz) and M740(1.73GHz): If i underclock the M780 to 1.73 GHz, will it generate the same heat as the M740, or different. Considering that both of them come off the same assembly line, and the number doesnt get decided until after they have been manufactured, common sense tells me that the underclocked 780 should generate the same heat as the 740. They both have the same TDP of 27 W as well. However, I have a gut feeling that this isnt the case. Can somebody help me out here, and tell me what is the real situation.
2) Consider the processors M760 and M755 (Both 2GHz). The TDP of teh 755 is 21W compared to 27W for the 760. However, Intel tells us that this doesnt mean that the 760 runs hotter than the 755. What am I missing here.

ciao
demi

[infinitevalence]

The tempreture of the cpu is a product of several factors, voltage, leakage, and operating frequency. There is a lot more to it but thats the base. When you increase any of the above the tempreture goes up. The 755 uses a 400mhz bus while the 760 uses the 533, some of the thermals may be from that. with the 2.26 vs the 1.73 the big difference is that they both run at the same voltage for different speeds. the 1.73 is only raited to run at that speed at default voltage. So yes if you underclock the 2.26 you should get a reduction in tempreture but only if you reduce the voltage as well.