Help With Stuttery Games in VM

[huggy3233]

On my proxmox server (R7 5700X, 48GB RAM, Proxmox 7.4, Kernel: 6.2.11-2-pve) I have a vm running Arch Linux for gaming with a RX 6700 XT passed through to it. In most games I see performance within margin of error of running bare metal, but some games, most notably Sea of Thieves and Forza Horizon 5 experience insane stuttering, despite reporting frame rates very close to what I get running them on a bare metal linux machine.
I've tried:

• Pinning cpu cores using taskset (I haven't worked out how to reserve them so other processes can use them).
• Changing cpu type to host
• Enabling hugepages
• Turning off all other vms and containers

None of these fixes have solved the problem, does anybody know how I could fix this?

 

[Dunuin]

Are you maybe assigning too many vCPUs to your gaming VM so PVE host itself got no ressources left to hypervise the guests? You only got 8 CPU cores, so I personally wouldn't add more than 6 vCPUs to a single VM.

 

[huggy3233]

I currently have it set to 12 cpu cores which I assumed meant 6 hyper-threaded cores, I'll try set it to 6 and see what happens. Also whats the different between cpu cores and vCPUs?

 

[huggy3233]

6 cores hasn't seemed to make a difference.