Why does the Fanxiang S790E cause texture delays?

Switching scenes in Remnant II, my S790E cache overflowed. Texture loading hit 8s. I increased page file to 32GB, but FPS dropped from 78 to 61. I used GamePP NVMe Queue Depth Config to set depth to 2048. AIDA64 showed 42-55℃ temps. CrystalDiskMark confirmed 68-75MB/s 4K reads. The delay is gone. I can backup my saves.