CPU at Max when trying to use Hardware Transcoding

[gary279]

Server Version#: 1.32.8.7639
Player Version#: 1.85.0

Hi Guys

I’m really hoping someone can help me and that it is probably a really simple solution that I’m just missing it because I have spent so long looking at it.

I started to build a new Plex server on an old PC and wanted to virtualise this using Proxmox and use PCI Passthrough so the Plex VM could access the GPU and allow me to use hardware transcoding.

I followed several guides both written and YouTube which all followed very similar directions so felt like I had a good understanding of the steps involved, however, when the server was finished, I tested playing 4K content which streamed with no problems using Direct Play, if I reduce this to 1080p, Plex shows on the dashboard transcode (hw) which suggests it is using the hardware to transcode but the CPU shoots up to 100% and if I run “nvidia-smi” it says No running processes found so it seems like it is not using the CPU instead of GPU.

After spending days trying to get this running from Proxmox, I reached the conclusion that my hardware setup will not allow the GPU to passthrough even though everything looks like it does. I also read and seen that this can be the case. I then reinstalled Linux onto the PC and setup plex directly on the hardware instead of Proxmox. I still have the same issue!!! I preformed exactly the same test and had the same results.

Below is some info on my setup.

PC: Dell OptiPlex 3010
CPU: Intel(R) Core™ i5-3470 CPU @ 3.20GHz
GPU: NVIDIA GeForce GTX 660

Setup Version 1 - Virtual Plex Server

Hardware as Above
Proxmox version 8.1
VM running Ubuntu 22.04.3 Server
Plex version as above.
GPU from https://uk.download.nvidia.com/XFree86/Linux-x86_64/470.223.02/NVIDIA-Linux-x86_64-470.223.02.run

Setup Version 2 - Plex on Bare Metal

As above but without Proxmox.

Happy to provide more info, logs, links to the guides I followed etc just trying to not make this post a 20 page essay.

Any advice, help or telling me that what I’m trying to do isn’t possible and give up now would be appreciated.

Thanks

[ChuckPa]

Look at the NVidia Decode - Encode Matrix.

Video Encode and Decode GPU Support Matrix

If I’m reading it right , your GTX 660 just misses the lower end for consumer cards and HW transcoding.

Your CPU, on the other hand, does have Hardware QuickSync video support for 720p and 1080p video

https://www.intel.com/content/www/us/en/products/sku/68316/intel-core-i53470-processor-6m-cache-up-to-3-60-ghz/specifications.html

You are probably getting the passthrough (especially if nvidia-smi shows the card then it’s there) but this is probably a case where the Nvidia can only be a display adapter for you.