Should I really have to do that? It's
No top case fan blowing down on the CPU cooler nor the VRMs. I thought that a top case fan should be used as exhaust since hot air rises. I don't have a top case fan. I did run Prime 95 v26.6 Small FFT for 5 minutes and my 5800x hit 89C after about 3 minutes and stayed there for the rest of the 5 minute duration. Frequencies were averaging around 4,470 MHz on all cores during the run. I also ran Prime 95 v30.3 Small FFT for 9 minutes and my 5800x hit 85C and stayed their for the rest of the 9-minute run. Frequencies were averaging around 4,183 MHz during that 9-minute run of Prime 95 v30.3.Do you have any fans blowing from top down on to the HSF / VRMs? I have one doing that.
Am running 5837 (same AGESA as your BIOS) on the PRIME X470-PRO, right now, prime95 Small FFT, I am getting ~80*C with a Gammaxx 400 and Ceramique 2 with the 5800X.
Try prime95 small fft to see if it stays around 80*C; IMHO I think prime95 is the 'best' stress test for a cpu.