My 1950X has the following p-states advertised via ACPI: 3.4 GHz (P0), 2.8 GHz (P1), and 2.2 GHz (P2). However, it seems unable to enter P1. It can transition between P0 and P2 with no problems, but setting P1 (2.8 GHz) fails. I have a report of the same basic issue — cannot enter P1, but P0/P2 work fine — from a 1920X user (although the P0-P2 frequencies are slightly different on 1920X).
Has anyone else on this forum played around with p-states on the AMD Ryzen (and especially Threadripper) platform? Can your CPUs enter P1? What motherboards and BIOS versions are you using?
I'm using an ASRock X399 Taichi motherboard, with no overclocking. I have the latest August 9 1.30 BIOS.