What and how does RAM impact performance in the sim_

32Gb of RAM is fine, and your 2080Ti has (I think) 8 or 10 GB of VRAM. Your current rig will do for a long time yet. If you watch Task Manager you can see the sim uses less than 6 GB of VRAM. That’s the one to watch. When the GPU runs out of dedicated VRAM it starts swapping to disk, and that can be a trouble spot.