BramVanroy:

So the only software requirement is that the installed graphics driver supports the CUDA version that you are requesting, right?


Yes, that is correct. You can find the NVIDIA driver requirements for different CUDA versions here 2.



 BramVanroy:

I remember that when cloning apex, the CUDA version number had to be identical (major and minor) to the version number PyTorch was built with. So in that scenario, I guess apex used the globally installed CUDA libs, and threw a warning when that differs from the PT ones.


Yes, that is also correct, since apex was built as an extension, thus you needed to compile it (which is why the “native” amp in torch.cuda.amp can be used directly without rebuilding).



 BramVanroy:

What I do not understand, though, is why apex could then not built itself using the CUDA libs that are shipped with PyTorch?


PyTorch ships only with the runtime libs, not with the compiler (nvcc), as this would blow up the size even more. I’m also not sure if you can even ship the compiler in conda binaries or pip wheels.