Does CUDA Cores matter when choosing a video card to build a short 3rd person game?
and
Does the engine even use these? I’ve seen some that have 384 to 3000 CUDA Cores.
It will not matter for UE4. In general, the number of CUDA cores don’t necessarily make a GPU better anyways (for the things that use CUDA).
In the case of UE4, they don’t want to rely on features that only work on certain brands of graphics cards, so there’s no optimization for Nvidia hardware. PhysX for instance runs off the CPU.