It is an issue my friend which is why custom full coverage water blocks are being made and why people are going out of their way to make contact plates that cover the entire heatspreader. A review site that actually does a good job of getting into such details highlight this here :
http://www.gamersnexus.net/news-pc/3008-threadripper-cooler-and-thermalpaste-coverage-vs-die-ihs
So no.. I wont put it to rest as it quite clearly is a thermal inefficiency.
DUH :
This is exactly what I highlighted in previous commentary and it is quite clearly 100% accurate.
So, as for Gur3d's coverage
FALSE. The heatspreader wont be bigger than the contact surface area of correctly engineered contact surfaces. Straight from their own contradictory website :
http://www.guru3d.com/news-story/ek-offers-amd-threadripper-supremacy-evo-water-blocks.html
As for this crap :
This does not show the thermal inefficiency issue as there is a huge area that's not being shown underneath the mounting bracket and even further in to the copper mating surface and subsequent outter surface that has screw holes that don't contact the heatspeader
directly above the die.
Per Guru3d's own words :
That being said, there is clearly thermal leakage if you look closely that is between a valuation of M2 and M4 7*degrees C. I'm quite confident its alot higher than that if you got thermal information under the bracket and then closer to the copper contact plate and above one of those screws. I'm quite sure its about 10-15*C difference which is a big issue w.r.t to potential warping and a friggin die that has some cores running pronounceably hotter than others. Just because Guru3d didn't do a sufficient job (arbitrary by their own words) doesn't make the case any stronger that these unspec'd AIO cooler contact surfaces are thermally inefficient and don't cover the dies. That my friend is factual as proven by the correct coverage by Gamer's Nexus in actual pictures under the brackets and under the copper contact plate. Again for your viewing pleasure :
See fin surface.. See screw holes directly above the die surface?