Why does my FPS drop from 144 to 60 during Destiny 2 particle effects?

During massive particle-heavy battles, my FPS would crash from 144 to 60, accompanied by the sound of fans screaming without actually cooling the CPU. I tried setting fans to full speed via BIOS; while temps dropped to 84℃, the high-frequency noise was like a power drill and completely unbearable. I used the GamePP Fan Curve Configuration to set a 74℃ trigger with a linear step increase up to 2200 RPM between 80-90℃. Cinebench R23 tests showed peak temps suppressed to 78-83℃ per HWInfo64, and HWMonitor confirmed stable core temps at 76-82℃.