Linux VM with NVidia HW Acceleration (NVENC working)

[Paruccone]

Hi,

HW Config:
PowerEdge R520 with:

• 2x E5-2430L CPUs
• 6x8GB 1600MHz ECC
• Perc 7i in ITmode (integrated on PCIe) with a bunch of drives
• Matrox G200 (integrated on PCIe)
• PCIe FC4 dual FC
• PCIe USB3 controller
• nVidia NVS 510 (headless, only needed for HW accel)
• NVME drive

SW Config:

• Proxmox 7.3
• Various VMs, we'll be focusing on the OBS one which has passthrough for the NVS510 only
  • Xubuntu 20.04
  • OBS from ubuntu rep (27.3)
  • nvidia prop driver 470 (late versions do not support NVS510)

Problem being that as soon as I start OBS with a single NDI source, CPU usage goes skyrocket high:

and the GPU is doing nothing:

I see 2 scenarios:

1. OBS uses HW accel only for encoding/decoding (no solution)
2. OBS should use HW accel but it's not whether because of the X-server being used (not using NV accel as the card is headless and display goes to virtual GPU from proxmox) or for some other reason.

Out by curiosity I started a recording and nvidia-SMI still shows no processes using the CPU: looks like OBS is configured to use NVenc but it isn't using it:

any clue?

PS: I gave up trying windows as I was able to passthrough the GPU only once out of 20 reboots...

Thanks!