Cant passthrough entire Tesla K80 - Proxmox with win10 guest

I’m having trouble passing my entire Tesla K80 through to my win10 vm in proxmox 6.4. the card will show up as two pcie devices in proxmox and I have had great success passing one of these devices in - with stable performace gaming and workloads.

However- when I try pass both devices I get a code 12… I can’t enable above 4g encoding and resolve the issue - I followed this guide whihck talked about addings args to the vm config file but I still get the code 12 - cant get enough resources.

Has anyonbe done this before? Or has anyone found success passing the entire card through?

any luck here? I’m trying to do the same but with Proxmox 8.1

make sure ‘all functions’ is checked and under ‘advanced’ check ‘PCIE EXPRESS’

also, is the VM you are trying to pass it too configured as Bios boot or UEFI boot?

VM is UEFI, I am able to passthrough the GPUs, but this is what I see in Windows VM

BTW, “all functions” should be checked where? in BIOS?

in the proxmox settings, this setting should force ‘all the devices’ for that GPU to the VM.


if your MB or something does not support ROM-BAR, make sure to leave it unchecked.

Tried both with and without ROM-Bar selected.
Selected PCI-Express checkbox, all exactly as in your screenshot.

I get same exact result.

Is there a way to hack BIOS and enable the above 4g decoding?

that is one example, there are dozens of guides depending on the mainboard style. Also, it is a low probability of changing your problem, and the most difficult thing to fix. so i would try it last.

one other thing to try is do an “lspci” on the host and add all the related nvidia devices directly to the VM config file. as well as trying an older Nvidia driver.

lots of things to try.

Thank you for the ideas. I will try as many of things as I can find instructions for :slight_smile: and i’ll try the hack, i don’t care if i damage the motherboard. I wanna make the K80 run on something :slight_smile:

One more thing. So the guide you shared is for Windows.

I’m guessing I can’t use this guide from a Windows VM installed in Proxmox running on the mobo I want to edit, correct?
I should install Windows directly on the pc. But then if the settings help, and my K80 works , will it still work after I reinstall Proxmox ?

you can do most of it from a VM, and the flash step itself would be done from however the mainboard recommends you flash the BIOS. there are guides available for linux also, that was just the top of google.

but yes, if you do the real flash method it will not matter what OS you load after the firmware flash, ROM-BAR would be available.

some boards have better modded support than others. it is all kind of a grey area for that stuff.

1 Like

didn’t work, the first software didn’t even open. tried different Windows machines, as soon as I open it, it closes.

I think i’m just gonna give up on this board.