Intel

i9 13900k + NZXT Kraken x73 aio

So I've been having an issue recently where my PC struggles with certain games and applications that used to run fine, unless I reduce the processor frequency (using Asus utility) in which case there's zero crashes. I used to be able to run The Division 2 at max settings no problem, but now it crashes after a few minutes. Same when rendering specific Blender scenes with lots of geometry and volumetrics. Before they would just take a while to render, now they just crash soon after the rendering starts. Most games and maybe like 80% of blender scenes work fine. It's just the really taxing ones that seem to crash.

One common thing I've noticed is that the crashes happen whenever the CPU is in heavy use so all the fans are ramped up, which could maybe suggest an issue with the AIO. But it idles at 35-50c, so why is the aio seemingly working fine there? And why does just the app/game crash but not windows if the processor is overheating?

I've not changed anything about the PC. It has the same offset voltage of -.05 that I've had for months and pl1&2 limits of 253W. This all just started randomly like two months ago. What I don't really understand is why lowering the clock speed solves the issue.

Tldr: Games and blender scenes that used to run fine now crash the app, especially demanding games and blender scenes. I've tried loading bios defaults, new windows install, repaste. Only thing that stops the crashes is lowering the processor frequency to ~3.5ghz through Asus utility. idk if it's the processor or something else.