Why does Palworld drop from 80 to 30 FPS on Fanxiang S790 4TB SSD?

Managing hundreds of Pals, I noticed FPS plummeting from 80 to 30 whenever saving or loading new areas. I tried enabling write cache optimization in the system, but it caused the system to crash and reboot twice, which made me very anxious. I accessed GamePP NVMe Queue Depth Configuration, increased the depth to 2048, and forced the write cache flush. AIDA64 showed latency stabilized at 30-38ms and temperature at 46-53℃, while MemTest86 confirmed zero errors.