Issues with NVIDIA Quadro M620 Mobile Passthrough on HP Z2 Mini – Need Advice

[theedude82]

Hi everyone,

I have a PVE cluster with three identical HP Z2 Mini computers (old CAD computers from my job i was gifted)—each with an NVIDIA Quadro M620 Mobile card. My goal is to pass through the GPU to an Ubuntu server 24.04 VM so I can run Plex for hardware-accelerated transcoding. Currently plex is running in a old i5 intel nuc.

What I’ve Tried So Far:

Custom ROM:
– I’m using the TechPowerUp ROM (230821.rom) placed in /usr/share/kvm/

Host PCI Settings:
– I’ve experimented with various hostpci0 configurations (e.g., using x-vga=on versus x-vga=off, and toggling rombar=0 vs. rombar=1), both with and without the ROM file.

CPU Flag Tweaks:
– I attempted to pass extra CPU options to hide virtualization (using -cpu host,kvm=off via the args field) to help convince the NVIDIA driver it’s on bare metal.

Observed Errors:
– Inside the VM, nvidia-smi always reports “No devices were found.”
– The guest’s kernel logs show errors like:
  NVRM: GPU 0000:01:00.0: Failed to copy vbios to system memory
  RmInitAdapter failed! (0x30:0xffff:1098)

I’ve tried every combination I could think of—but the mobile GPU still refuses to initialize properly. It seems that many mobile GPUs (including this Quadro M620 Mobile) don’t expose a usable UEFI VBIOS for VFIO passthrough.

My Hardware Details:

Hosts: HP Z2 Mini computers (three in a cluster)
GPU: NVIDIA Quadro M620 Mobile (one per host)
VM: Ubuntu server 24.04 (target for Plex transcoding)
My Question:
Has anyone successfully passed through a mobile GPU like the Quadro M620 Mobile on an HP Z2 Mini?

Has anyone managed to extract or use a valid UEFI-compatible VBIOS for this card (perhaps from a Windows install using GPU‑Z or a similar tool)?
Are there any additional configs or known limitations with mobile GPUs in Proxmox that I might be overlooking?
At this point, I’m considering moving to a system with a desktop-class GPU—but I’d love to learn if there’s a known workaround for these mobile GPUs.

Thanks in advance for any insights or suggestions. I’m happy to provide additional logs or configuration details if needed!

Erik

 

[szaboldi]

Hey, having the same problem. I spent almost all day with this. Did you manage to get it work?

 

[theedude82]

I could not get it working and dont think I'll be able to. Sucks

 

[szaboldi]

What do you think if i install windows on it extract the VBIOS and use that would it work or at this point it's just wasting time? Or would it be the same as the TechPowerUp ROM (230821.rom) ?

 

[theedude82]

When i asked chatgpt for help, it suggested i try that, but I don't have any Windows computers. I have a feeling it wont work either but if you have the resources i'd say try it out and see what happens.