Video card RAM (VRAM) is usually the limiting factor for AI. I found a more recent Github page:
A unified framework for 3D content generation. Contribute to threestudio-project/threestudio development by creating an account on GitHub.
github.com
"You must have an NVIDIA graphics card with at least 6GB VRAM and have CUDA installed."
It looks like more VRAM can make it faster.
A 3060 12GB is probably the minimum you should even consider. What's your budget?