Guidance for GPU Passthrough

[Sidewinder]

I'm hoping to get some guidance with Unraid VM GPU passthrough (first time trying this). I'm currently testing this process and have been running into several issues along the way that I've been searching the forums, reddit and watching videos on and I'm not really sure what to do as a next step.

 

Mobo: MSI Tomahawk B450

Video Card(s) for Testing: nVidia GT210, AMD HD6750

 

Things I tried and learned:

1) First tried only the one GPU then learned that Unraid uses it in the first slot

2) Tried dual GPU but learned that the MSI board has the lower slot IOMMU group contains one of the USB controllers AND the Ethernet controller. This lead to Unraid not having a network when I tried the vfio syslinux config method (which makes sense)

3) Found some suggestions for booting Unraid using vfio config method with one GPU, which was supposed to force Unraid to not initialize the GPU. This worked at first, but the VM wouldn't display anything, then when I tried to reboot the system Unraid would no longer boot.

4) Tried removing the configuration then all the video cards to start over tomorrow, but the system refused to boot without a card.

 

Is there a way to:

1) Force Unraid to use the second GPU slot for the console (which it is doing now, first slot is empty)

2) Force Unraid into headless only and leave the GPU alone

3) Anything else I have been missing?

 

I'm hoping that my only option isn't ACS override as I'm concerned about network services (unless this is unfounded). I have considered replacing the motherboard, but I would prefer if Unraid would just leave the GPU alone.

[JonathanM]

One option you could try is looking in the BIOS for a setting that controls the primary GPU.

[Sidewinder]

On 3/16/2021 at 11:02 AM, jonathanm said:

One option you could try is looking in the BIOS for a setting that controls the primary GPU.

Sorry had a busy week. I don't remember seeing that as an option, but I'll take a second look to make sure I didn't miss anything.