My theories:
Some glue-like viscous substance to eliminate cross talk.
Something thermal/temp related?
Other, something for optimization
Something that was used during creation of the CPU and was left behind during manufacturing
Other's theories:
Obfuscation/censoring for the Chinese press...
For this to make sense, look at the EPYC's infinity fabric. You see how all the dies are connected to one another, why can't this work for compute clusters? Instead of having 1 master processor and multiple slave processors, why don't we have them equally connected so any processor can talk to...
My area has many "pop offs" where the power goes suddenly off due to a short to ground somewhere in the local area grid, and then comes right back on (usually). Causes my computer to restart, sometimes not successfully, but I lose everything I was doing. When it's unsuccessfull I have to flip...