I have a AMD 7950x on a Gigabyte x670e Aorus master with a Nvidia 2080ti GPU and 64GB ram.
Now I have set the BIOS to use the iGPU and force it as well, however when I try to boot Linux GRUB appears on the dGPU. What is the deal??? I had no problem with my Intel set up. All I wanted was to upgrade. Why does AMD have to be such a PITA?
it is really more of a linux addressing thing, and can happen with any brand of hardware, it just happened to catch you with a brand change. this also happens a lot with laptops that have a dgpu plus cpu with an igpu, the instructions are the same besides needing to use the correct display ID. anyways…
rather than typing or doing a copy pasta, heres a link to a correct set of instructions.
My experience on this subject isn’t exactly the same since my home server’s CPU (5950X, AM4 system) doesn’t have an iGPU, but I experienced something similar. I have a 3080 Ti along with a GT710 in my server. The 3080 Ti is obviously for passthrough to a VM, the 710 sits in a PCIe 1x slot for some basic display output on the host OS.
The ‘trick’ in my case was to play around with the UEFI/CSM setting in the BIOS, more specifically I had to set it to UEFI and I also added ‘video=efifb:off’ to my kernel command line, I frankly don’t remember whether it was required to get things to work or whether I added it while troubleshooting and never removed it. GPU passthrough works flawlessly now.
The way my home server behaves currently is that GRUB is actually displayed on both cards, but once Linux actually begins loading the 3080 Ti no longer updates. The “Loading initial ramdisk” message is printed and then the 3080 Ti no longer updates at all until the VM picks it up, at which point it starts displaying the VM’s boot process.