I recently built a new workstation, and my primary workstation has always been OpenBSD and Windows 10 dual-boot. I mostly stay on OpenBSD, but occasionally switch to Windows 10 when there’s some video game I want to play that I can’t get working on my Macbook. I mostly only play FFXIV and World of Warcraft, plus the occasional indie game on Steam, so my Macbook solves about 90% of my gaming needs, but maybe once a year something comes out that only works on Windows and I want to give it a go.

So when I built this new workstation, there was a nice deal on last year’s big fancy AMD graphics cards and I decided to buy an RX 6750XT. The version of amdgpu(4) that is in OpenBSD supports the chip that’s in this card, so I figured we’d have no issues. Unfortunately, I could not get amdgpu(4) to init and it would crash during startup.

Long story short, a feature of my BIOS was causing the problem. There is a GPU feature called Resizable BAR Support that, when enabled, causes some AMD cards to not init properly. I’m not sure if this is an OpenBSD specific bug or just generally an issue with amdgpu(4), but regardless disabling it was what fixed the problem for me. Here are a few screenshots showing the steps required for my specific BIOS. Hopefully yours is somewhat similar