[SOLVED] Passing through PCI Device, what is PCI-Express for?

[ozioh]

Hi,
I am trying to understand whether to select PCI-Express option in Add - PCI Device (advanced portion ) in VM hardware options.
What should my selection be for

- GPU (PCI-Express is selected)
-PCi adapter with an NVME PCI4 device (PCI-Express not selected)

My machine is q35.

Thank you,

 

[dcsapak]

it's mostly to be compatible with different guest drivers. some are a bit picky when it comes to that. if it works with pci, you problably won't gain anything switching to pcie, but it shouldn't hurt to try and see
what is better always depends on the hw, guest os and guest driver, so we cannot give a general recommendation either way

 

[ozioh]

Thank you so much for your answer.