Given the sheer size of the heat spreader on Threadripper CPUs there are, understandably, concerns at how to correctly apply thermal paste for best possible heat transfer. I understand that under the heat spreader, having seen one that has been delidded, there are four modules, two of them being dummies. Would this not lead to the areas of the heat spreader over the active modules being somewhat hotter than the areas over the dummies? I understand that the active ones are diagonally arranged but there is no way to tell which way from the heat spreader.
What if the Threadripper heat spreader was segmented, something like a chocolate bar? (How thick is the heat spreader?) If there was at least one groove across the CPU (or two, dividing it into four) this would help to guarantee an even and effective spread of thermal paste over the whole surface area - one good blob of thermal paste on each section of the heat spreader with the groove(s) allowing for elimination of air and excess TP. Tests have shown that it is important to get a full coverage of thermal paste across whole of the heat spreader, right to the corners, for maximum cooling.
In the past it has been said that the less thermal paste you use between the CPU and the cooler the better for heat transfer. On a large area such as with the Threadripper, I would guess that the thickness of the thermal paste would naturally be thicker when applying enough to guarantee full coverage but with a segmented design it could be thinner and more effective.
Something to look at?
Yes, I am aware of this. Notice the photos in this article all showed a round water block which does not cover the entire heat spreader. Other tests have shown that where the water block covers the entire Threadripper heat spreader cooling is significantly better. The new Enermax LIQTECH TR4 360 is one such cooler. It is with such coolers I am concerned with the reliability of the spread of thermal paste and the quantity, contributing to the thickness, considering that with a larger area being covered the pressure exerted will be lower per unit of area. I don't know how the viscosity of various thermal pastes compare but that would be a factor on such a large area.
That would all depending on how many cores - 8 cores have a small die area of ~1cm wide x 2cm high while 32 cores have 4x the 8core die size. However, the 32core die size overall is no more than 4x2cm hence pretty small. No science needed just place the blob and slab the heat spreader on. Don't fall for all that marketing gimmick coz they just want to justify a $1000 price tag. The huge CPU size is just a result of the 'million' pins.