[Request] ASUS PRIME X370-PRO ATX Boot with GPU in Slot 2 or 3 activated. Not GPU in Slot 1

Hello members,

I am new to this whole topic of BIOS modding. Hence, maybe I am requesting something impossible. Please forgive me in this case.

Background: I am trying to set up a Linux installation with a Windows 10 virtual machine with GPU passthrough. This enables to run Linux (Ubuntu 18.04 in this case) and Windows 10 on the same host without the need of dual booting. If you are interested, here you can find out more.

For setting up the GPU passthrough, the GPU used in the Windows virtual machine, has to be made “invisible” to the host Ubuntu system. But doing this, only is recognized late during startup of Ubuntu. my only solution so far would be to swap my GPUs. But as I have not enough physical space for the Gigabyte nvidia 1080 ti in the 2nd PCIex16 slot, I hope for a BIOS / UEFI configuration option to use the PCIe slot 2x16 or 3x16 on my motherboard for booting up.

Is this possible?

Thanks in advance!

@mongole - Maybe disable “Fast Boot” setting, could help possibly? Look through your BIOS completely using AMIBCP, if you see any settings you need changed, or made visible, I can help with that.
Maybe you’ll see some that would help that I didn’t recognize. Latest version here
Be sure to look in the debug folder (with no name) within the “Main” submenu. Some graphics related settings at Advanced >> Onboard devices config, but maybe nothing that would help. And also ADV >> PCI Subsystem Settings
I could not find anything where you’d be able to pick which exact card/PCIE slot is used at startup