How to fix the frame rate drop after 2 hours of playing Silent Hill 2?

Walking through the fog, the originally smooth 60 FPS dropped to 35 FPS after two hours, a decay that felt like a bad joke. I tried restarting the game, which provided temporary relief, but the problem returned after 30 minutes. I enabled the GamePP Resource Scheduler to force redundant cache cleaning every 30 minutes and locked memory priority to the highest level. RTSS showed intervals converged from 25-50ms back to 16-22ms, with HWiNFO64 recording 48-54℃.