When I was deciding whether to purchase 10900X or 10920X there was very little information available but I knew that 900 has slight base core advantage, 920 has slight max boost advantage, they are same at all core boost and have same TjMax. Two more cores doesn’t make a difference to me but it matters a lot to me if one CPU will generate less total heat when every core runs at same clock (would “have more thermal headroom” be correct term?).
 
Not having any info on temperatures I speculated if all cores on both CPUs ran at same speed 10 cores of 10900X will generate less heat than 12 of 10920X and purchased 10900X.
 
Now, in a typical case of post-purchase second guessing, I am wondering did I make a mistake with that assumption but still can’t find any info on temperatures of these CPUs that would let me compare them in apple-to-apple manner.
 
Can anyone, please, comment on assumption I was making, is it correct, or can point me in direction of data that would answer question does 900 have “more thermal headroom” (assuming all cores are running at same clock)?

Monstieur
I have a 10900X and EVGA CLC 280. Some cores exceed 100 C during stress testing when overclocked to 4.9 GHz @ +35 mV. The 10920X being a better bin with higher Turbo frequency might overclock better with lower voltage, but the 2 extra cores will definitely add more heat overall. The 10920X is still the better chip and in the worst case you can disable 2 cores in the BIOS. With a strong liquid cooler, these CPUs only overheat when running stress tests. You can run 5+ GHz all-core and not overheat in real-world applications & games, so you can even get a 10940X.
 
I wish I had gotten the 10920X with a better bin after seeing what a great overclocker my 10900X is.

I'm not looking to overclock. What I need is bigger "safety margin" heat wise when both CPUs run at same clock per core because room this machine will be in does not get cooled even during Southern California summer.

Monstieur
Temperatures are a non-issue for gaming / desktop usage. You can get any CPU and it will run below 70 C.

Thank you! If you end up having time to humor me I would be curious to hear what kind of temperatures you are getting from stress test that is part of EVGA’s BIOS. Running at same settings should let me compare apples-to-apples and figure out do I want 10920.

Monstieur
That's a weak test. I use LinpackXtreme and Prime95 and it hits 105 C.

I know it is not as strong of a test as others but it would give me some apples-to-apples-idea and I don't have Windows installed yet.