Along with die shrink and new trigate adding to heat issue, turns out intel did indeed use paste for ivy bride die attach picture proof of delided ivy with paste tim
. So part of high temps is because not using solder 80 w/mk thermal conductance + thin bondline of solder, and instead using paste tim which will not only be applied thicker but also much lower bulk thermal conductance.
For running stock settings at low voltage, probably only a few C difference between paste and solder TIM, hence intel can save money by using cheaper paste. But at overclock settings and higher tdp, going to make a significant difference in core temps, sucks for overclockers, but intel doesnt design chips for us.
I guess only the more expensive enthusiast cpus are now getting solder tim (assuming they are)...kinda sucks for overclocking. Wonder if they use paste/solder for xeons...though probably same paste for same corresponding xeon, but when they come out, maybe will see.