asrock x370 Taichi P0 not sticking in bios

[yossarian]

I flashed to the 4.40 bios on my x370 Taichi and now when I try to set P0 to custom it resets to auto after saving and rebooting. Also, the core boost disable resets to auto also. This with an 1800x. Prior with 3.2 bios trying to set P0 resulted in no post and having to reset cmos. This is my second board and processor. I thought I had failures with my first set but I think I traced it to a problem with my Samsung 961 NVMe that I removed from this setup and is now running fine with my older 950 Evo SSD. That original board and processor ran fine with a custom P0 setting. I've tried a0 (4 Ghz) and 9c (3.9 Ghz) and neither "sticks". Not sure if it's the new bios or the hardware or both.

 

[yossarian]

I think I found the solution so I'll post it here in case anyone else runs across it.

I think in the new 4.4 bios there is a new setting in the OC Tweaker Screen called OC Mode Change Switch. In that setting it defaults to ASRock Setting. The other choice is AMD CBS Setting. When I switched to AMD CBS Setting, the options I picked in the Zen Options - P States remained after saving and rebooting. I'm not sure what the ASRock setting does.

 

[SliceT]

Probably is a more conservative overclock stage on the X CPUs? would be interesting to know..