deep-learningLearner:

Cuda vtoolkit 1.5 is not supported by Pytroch , so need downgrading of the toolkit to 11.3


No, that’s not the case as I’m using CUDA 11.5 in a source build as well as the current CUDA11.3 nightly and stable conda binaries and pip wheels.



 deep-learningLearner:

There are different similar directories in /usr/local/ and Pytorch is confusing which to use. There are “cuda”, “cuda-11”, and “cuda-11.5” folders in /usr/local


The pip wheels and conda binaries use their own CUDA runtime as specified in the install command. Your local CUDA toolkit will only be used when you are building PyTorch from source or a custom CUDA extension.
To run the binaries you would only need a properly installed driver.