Hoot (Jul 18, 2001 08:01 a.m.):
I don't recall the exact value, but I believe the core only sits about .036 inches above the ceramic substrate. That is not a lot of additional surface area. All the same, I also toyed with the prospect of doing some precision milling to not only inset the core, but also all the surface mount components, so that the HS baseplate mated with the core at the same it met the ceramic.
People poo-poo this because it causes more of the core heat to take a different path (through ceramic) to the HS. I believe that any parallel heat conducting path, no matter how resistive, is a plus in reducing the core temp.
Consider you car engine. The design is for the heat in it to get removed by the water cooling system. Some still gets wicked away in the motor oil, transmission, etc. Those secondary paths help lower the temp a little bit and in the case of the CPU, every little bit helps. It certainly would screw with your in-socket thermistor readings, but who's worse off? The person who's thermistor reads too low, or reads too high?
This point is mostly moot and for the same reason, I did not pursue it. Namely, how many OC'ers have access to a decent mill? Documenting and writing it up for publishing as an article would not benefit many people while constituting a lot of work.
Now don't crowd each other, stepping up to take a swing at my logic. ;D