Why does the Kioxia EXCERIA G2 cause loading lag?

Crossing dense forests, my Kioxia EXCERIA G2 hit a PCIe 3.0 limit. Loading jumped from 5s to 12s. I set virtual memory to half disk space, but frame drops worsened. I used GamePP Hardware Sensor Page to monitor load at 45-52℃. I optimized storage strategy. CrystalDiskMark showed 2100-2200MB/s reads. Bandwidth hit 92-95%. It's fast now. I can export logs easily.