Hi,

 

I currently have a system with 2 GPUs (2 RX480s).

I'm planning to buy a third cheap gpu to boot unraid on and passthrough the other two to a W10 and a macOS VM because I can't passthrough the GPU Unraid is using (therefore can only use one of my 2 VMs at a time)

 

I was wondering how Unraid chooses the default GPU to boot on.

Does it prioritize the ones with monitors attached to them ? Is there a config file that would allow me to change the default GPU on next boot ? Or does it simply use the first GPU available when scanning the PCIe slots starting from slot 1 ?

 

Before you ask, I don't have any option to change default GPU directly in the BIOS, and I don't have integrated graphics.

 

Thanks

Unraid chooses the GPU that the bios sets as the primary adapter. Normally this is the one in the top pcie slot. 

Usually you should be able to pass through the primary adapter when it's an AMD gpu. Have you tried dumping the bios and use it when you pass the GPU through? 

Hi and sorry for the late answer.

 

It seems to work when I passthrough the primary card only on some VMs. I'm having issues with macOS Mojave (can't passthrough), but it works with GParted or the Acronis bootable media, so I guess it is a Mojave related issue.

 

Thanks, I'll probably ask on the Mojave topic

@vxch Did you ever solve this for MacOS VM? Or did you just change to the secondary GPU slot?

 

Br,