Why does Primal Carnage stutter during large combat scenes?

Watching the screen freeze for 0.x seconds during intense combat made me anxious; such stuttering on a PCIe 4.0 drive is unbelievable. I tried increasing the virtual memory page file in the system, but loading times lengthened and frame drops actually increased. I enabled GamePP NVMe Queue Depth Configuration, increasing the depth from 1024 to 2048. Random read improved from 45MB/s to 68MB/s per CrystalDiskMark, with temperature stable at 48-55℃ per HWMonitor and I/O response time at 120ms per AIDA64, hitting 68MB/s