In essence, it’s a matter of your passthrough graphics card being initialized during system boot. There are several ways to prevent that, or you may need to load a romfile to supersede the shadow BIOS.
Thanks for the help, I will update as soon as things are working 100%!
EDIT:
Up and running. Thanks again for all the assistance. As soon as my testing is done I will put a summary above the OP in case anyone else runs into a similar set of issues.
What a ride - but in the end your persistence paid.
As you wrote, your motherboard defaulted to PCIe slot 1 as the primary VGA to boot with. So switching graphics cards was an easy solution. With PCIe 8x speed this should not impact graphics performance.
However, did you have a chance to try loading an unshadowed ROM file as suggested in my previous post?
Even if you don’t try that, it might be a good idea to create a ROM image from your 1080 GPU, as described in Primary GPU Workaround.
Thanks also for documenting your steps/workarounds so that others can benefit from your experience. Hope you don’t mind me linking to your post.
Hi there and great job making the passthrough work on your system. I see you still have the Virtual processors showing in task manager. In case that’s still the case, you might want to try “host-passthrough” cpu model instead of any other options available. Here’s the explanation. The video isn’t mine, I only found it looking for cpu pinning documentation. Cheers.