TLDR: 7900 XTX is really quite good in VR now.
It's really quite good now. I use this card. Upgraded from Nvidia 3090 to 7900 XTX and it was a very positive improvement in performance. If you're just running VAM it'll give you pretty good framerates plus plenty of VRAM to store stuff in working memory. Think of the 7900 XTX kind-of like the Nvidia 4080, but with more VRAM. A 4090 would be better of course.
I currently run VAM alongside Voxta on my 7900 XTX. Voxta uses the 7900 XTX with the ROCm preview release of LMStudio to run a local LLM. This all fits in the GPU's memory alongside VAM. I use Voxta cloud for the text to speech and speech to text, since that's not support very well on AMD in Windows yet, but the LLM runs locally.
What this really boils down to is the GPU is under a lot of load running both LLMs and VAM, so here's how it breaks down on my system:
I use AMD's software Radeon Chill to cap the VAM frame rate at 45 FPS. Using Virtual Desktop on a Quest 3, I use the synchronous spacewarp which provides 90 FPS pretty consistently in-headset (and it looks great). All the while the GPU is also able to run the local LLM, so I'm impressed.
My graphics settings in VAM are pretty high:
Render scale 1.25
Shader quality High
MSAA 4x
Pixel light count 6
Smooth passes 2
Glow effects Low
Process priority High
Physics Rate 45 Hz (remember the FPS settings above)
Physics update cap 1
High quality physics Checked
I may end up running a 2nd GPU to offload the LLM processing to pull even more out of the 7900XTX for VAM, but even as it is, it's working sufficient for me. Of course it depends what kind of scenes you're going to run as well.
