Why does Naraka Bladepoint FPS swing between 80 and 40?

In dense combat, my fluid striking sensation was ruined by instant stutters, with FPS jumping wildly between 80 and 40. I first tried lowering texture quality; while raw FPS increased, the stutters remained, leaving me exhausted. I then used the GamePP NVMe Queue Depth Configuration to increase the queue limit from 1024 to 2048 and enabled the forced write cache flush policy. Frame generation time converged from 12-30ms to 11-16ms per RTSS, and drive temps hit 45-58℃ per AIDA64.