Why does my FPS drop during large battles in AC Valhalla?

During a massive charge on the Northumbria battlefield, the frame rate plummeted from 75 to 32 fps via GamePP Sensor, ruining the flow of battle. I first tried manually locking core frequencies in the BIOS, but this caused two memory checksum errors during boot, which was very discouraging. I used the GamePP Resource Scheduler to raise the game priority to Real-time and bound critical physics threads to high-performance cores. Frame generation time converged to 13-17ms via RTSS, and AIDA64 confirmed CPU temperature stable at 65-72℃.