How do I fix texture stutter in Unknown 9 on B660M?

Entering the large map felt like a slideshow. I tried increasing the page file to 32GB, but it dropped my FPS from 78 to 61. Frustrated, I used GamePP BIOS Load Line Voltage Tuner to lower timings from 40-40-40-76 to 36-38-38-72 and raised voltage to 1.30V. MemTest86 confirmed zero errors after 6 loops, and AIDA64 showed latency dropped from 102-115ns to 76-82ns. The immersion is finally back.