[pHaestus]

Bill a question about your heatpipe:

If you go low enough in power applied do you see a flat C/W vs power region? I'd expect that you'd hit a point where there isn't enough heat to cause a phase change in the pipe. Then if you keep boosting power over the heatpipe's working range far enough does it return back to that same flat line? Where you just add so much more heat into the system that the heatpipe doesn't work because the cold side is too hot?

I am visualizing a situation where at really low and really high power (temperatures completely outside the heatpipe's operating range) that you get performance that is pretty similar to just the heatsink alone, and that only within mfgr specs is there a big improvement by adding a heat pipe.

I have never personally used a heat pipe though so I could be way off base about how they supplement convective cooling...