Nvidia SLI and PhysX configuration

[n00rp]

I'm tweaking a few Nvidia settings and wondered if VAM would make use of, or see any performance boost if I dedicated one graphics card to PhysX? Currently it's set to auto select. I already have SLI switched on, but have no idea if VAM makes use of it. Settings below...

 

[an3k]

VaM uses the Unity engine and that uses PhysX. However, the Unity developers were so intelligent and took the nVIDIA PhysX, stripped the GPU support, stripped the multi-threaded support and hard-coded it into Unity so you can't the nVIDIA PhysX even if you want to.

TL;DR: Unity PhysX is not able to run on GPU but just a single CPU core.

 

[meshedvr]

PhysX in Unity is actually multi-threaded for the solver and many other parts, but there is a main-thread bottleneck where Physx native objects have to be synchronized with the Unity game objects, and that is where most of VaM 1.X performance issues lie. 2.X will attempt to correct this by using custom DOTS and/or GPU physics as much as possible and avoid Unity's Physx implementation and the issues it has.

 

[Guy]

@meshedvr if you're able to support dedicated GPU Physx, I think some would use it if it helps. FWIW.

 

[meshedvr]

@meshedvr if you're able to support dedicated GPU Physx, I think some would use it if it helps. FWIW.

Unity's Physx is their own custom implementation that does not support GPU acceleration, so that is not an option. Unity also doesn't really support a 2nd GPU in any way with compute shaders, which is a bummer because a 2nd GPU could be used for clothing/hair physics with results transferred to 1st GPU for rendering. That would be a big win.