Similar issues. all stock speeds
cooler master H500 with x2 200mm front intake 200mm top exhaust and 120mm rear exhaust.
Noctura 15SE dual fan blowing to the rear exhaust
PCI dual fan blowing air up.
x570 taichi
3900x
EVGA black 2070 super
Running Furmark for about 1 hour gets me to about 72-73 on the SB. I also setup a more aggressive fan curve, GPU maxes at 72 during Furmark stress test.
Adding the top and PCI fan did nothing to the temps.
Asrock told me to RMA the board, pretty sure its just bad design though.