I am running a full custom loop, on the following gear:
3950x (Stock + 0.075v undervolt)
Asus Crosshair VIII Formula (no need to add loop for VRMs but did it anyway)
64GB 3600MHz Trident-Z
Asus Strix 2080ti OC (standard clocks)
Soft-tubed loop consisting of EK blocks + 2 Rads - 120mm between 2080ti & VRM / CPU; 360mm between CPU and D5 pump
CPU temps are high 80's, graphics card high 50's. Water temp mid 30s.
I am only running folding on 6 cores + video card, have left my old 1950x (with 1080ti) to do most of this duty.