Why is my Noctua NH-D15S showing huge core temp differences in Atomic Heart, causing frame drops?

I'm using a top-tier air cooler, yet I was getting stutters during complex physics scenes—it was honestly ridiculous. The sensors showed a core delta of 15℃, meaning the base wasn't sitting flush on the CPU, causing some cores to throttle. I first tried lowering all-core clocks in the BIOS, which stopped the stuttering but killed 20% of my performance; a total waste of hardware. I eventually tore the whole thing down, swapped to a higher-conductivity paste, and tightened the mounts strictly to torque specs. AIDA64 tests showed the delta shrink to 4-7℃, with peaks at 72-78℃, and the stuttering completely disappeared. I actually messed up the first re-install by using too much paste, which leaked everywhere, so I had to clean it with alcohol and start over. Now the fans sit at 1100 RPM and it's whisper quiet. I saved the curve in the BIOS, and the game finally feels responsive.