3900X on AGESA 1.0.0.4B on Asus X570 Prime Pro
Windows 1909 1usmus universal plan 1.1
Regardless of PBO being disabled or enabled, maximum clock hovers around 4.55Ghz.
Cooling is powerful enough, 420mm Alphacool setup with 6 SilentWings 3 fans, on liquid metal, temps are kept below 60C up to 10 cores of sustained load, even with CB15/20 MT load (24 threads) they never exceed 66C on stock. Anyway, bios have CPPC, and idle power control but not CPPC preferred cores, I suppose it is enabled but hidden.
1 thread load uses core2 (gold one) on CCX0 but using 2 threads see the second thread default to core0 on CCX0 instead of core4 on CCX1 (silver one), increasing thread count to 3 brings core1 to work and further using 4 threads brings core3 to work instead of core4 (silver). So it seems that CPPC does not work correctly.
I suppose that I can't reach 4.6Ghz due to thermal constraints, but I simply can't cool the CPU below 50C, even 1 thread load hovers around 55C, even undervolted by 0.0625 (the lowest stable voltage - offset actually works on this board) I can't get it below 53C. Oh well, on 1.0.0.3 ABBA I could get 4.625Mhz.
Anyway, for now, the best approach for me is per CCX overclocking in BIOS (that actually also works well), I can get CB20 stable at 4.55Ghz(CCX0), 4.50(CCX1), 4.4(CCX2-3) and 1.475V (FIT limit) and gaming stable at 4.6/4.55/4.4Ghz at the same voltage - all due to temperature differences (CB20 MT tops at 93C and gaming rarely jumps over 82C).
I can get 7800p in CB20 out of this configuration -
https://drive.google.com/open?id=1s2XPkib51TlRIGxZ3oUo6MyvqGH6ji7R
I can only hope that AMD can get us our 4.6Ghz back with future AGESA version.