sounds like your throttling at extreme load. which means 1 of 2 things.
you need better cooling,
you need better cooling
but yeah them chips run hot full load between 85 and 95 on a 360 aio is not uncommon and apparently within spec.
(if your already running 360 rads you could try reducing your volts a little and still remain stable.
it should knock 2-3’c for every 0.1v you can save.
but only really applicable with motherboards that are overly generous with there chosen stock volts.
so maybe check your volts against another manufacturers default specs and see if your chip will run at there power settings.)
I have a 5900x and was seeing similar temperatures as you on a 280 rad (ibuypower) when under load. I have since upgraded to a 360 (LianLi Galahad) and the difference was huge. Well worth the upgrade for this chip, in addition to a better airflow case.
Check paste application, check your fans aren’t fighting other fans in your case, check if your GPU is heat soaking your CPU by dumping a heap of heat into your case which isn’t being effectively evacuated (I have this problem at the moment with my box; I swear most of my CPU radiator heat soak I see is from the air cooled 6900XT when its working hard )…
Are the fans on your h115i (which I also have) extracting from the case or sucking into the case? Are they fighting other fans in terms of flow?
Without GPU load I can run ~4.1-4.2 ghz sustained on my 2700X with temps in the 60s… which admittedly is only 8 cores, but its also on a much shittier lower clocking process. I’m not overclocking, just relying on motherboard’s PBO
I had an H105 GTX on my 1700x, 2700x and then 3900x for years. The 3900x would hit 82C max under 100% burn in/stress test with y-cruncher or prime95. That is a 240mm with a wider radiator (i think 35mm wide).
it had a lot to do with the choice of aio is my guess.
probably a re-issue with a new mount. which would be fine for intels 1 chip in the centre approach.
but the spread out amd chiplet’s?. that would need an internal redesign for the heat block which isnt cost effective for some.
end result your aio fits but isnt as effective as it should be for that chip.
Confirming, I fixed this problem and I can now hit 4.350 on my 2700X on a single core and bench about 5-10% faster in 3dmark now the GPU isn’t heating up the AIO radiator as I’m using the rad as an intake (instead of exhaust, which was exposing it to the GPU’s heat soak).