I rarely post in these types of threads, well, because I have no background for it.
However, it seems to me that the conditions in dispute could be easily satisfied by using a TIM with a known thermal resistance value, like those pads Shin-Etsu makes. The construct a heat source thusly. Make a heat die the size of the actual core on an A64 or P4 or whatever, then apply pad, then attach a fabricated heat spreader to this assembly and place another pad on top of it, then attach waterblock. Time consuming and expensive as you would need to re-apply pads between tests (maybe they would do for a while, I don't know). Then extrapolate data based upon known thermal resistance of TIM.
Forgive me if stupid, I tried
