Hm, are you installing it via pip wheels or source code? Because as far as I understood, PyTorch would be using it’s own CUDA parts when you do the regular pip install (i.e., wheels; pip3 install http://download.pytorch.org/whl/cu90/torch-0.3.0.post4-cp36-cp36m-linux_x86_64.whl ). So, my understanding is that even if you have locally CUDA 9.1 installed, it would be using the CUDA 9.0 parts that it comes with. Based on
conda binary has its own cuda, it doesn’t use system CUDA at all.
(There’s probably no way to tell which CUDA version PyTorch is using via the Python interpreter?)