Ever since installing a BIOS with AGESA 1.2.0.0 (and now 1.2.0.1) my machine locks up on multicore loads. It also will lock up while navigating in the BIOS. My original BIOS that supported Zen3 was 1.1.8.0 and I had no problems whatsoever, and I was tinkering with it then far more than now, since the build was new and I was excited for it. The problems started immediately upon the newer BIOS being installed, and they put a read/write lock in the 1.2.0.0 release so I can't flash back.

I normally don't update unless I need to, but they advertised so many fixes that I felt compelled. It's reproducible, I can lock it up immediately upon starting Prime95, and it'll occasionally crash running CBR20. I would hope over time, probably take a year or two, they'll get this sorted out.. but I may just order an i9-10850K and a Z490, and be done with this. I run bone stock UEFI BIOS settings, no PBO or other overclocking.

I run a small business off this machine, and it has to be reliable, performance doesn't matter if you have stability issues.