Why does UE5 stutter on JGinyue X79 PRO during physics scenes?

I was angry at the 45 FPS drop in clouds. I tried Performance mode, but E-cores still lagged. I used GamePP BIOS Load Line Voltage Wizard to set VCCSA to 1.23V. Cinebench R23 scored 34200 points. HWiNFO showed temps at 75-82℃. This backup ensures stability.