Understand PyTorch Install Command

When I select:
PyTorch Build: Stable (1.3)
Your OS: Linux
Package: Conda
Language: Python 3.7
CUDA: 9.2

It gives me this command:
conda install pytorch torchvision cudatoolkit=9.2 -c pytorch

My Question is, what does this mean?
(Let me give a starting but not complete answer to my question so you may understand me better. )
Answer (initial): The command means, you will use ‘conda’ package management software to install pytorch (1.3?) and torchvision (0.4?) which is pre-compiled with cuda library version 9.2. (Please correct the first part if it is incorrect or not complete) In addition, what is the ‘-c pytorch’ in the end?

-c pytorch means from the Pytorch anaconda channel, i.e. packages prepared by the PyTorch team (sometimes I think Soumith himself does that).

The pytorch and torchvision selects the latest packages available on that channel (where the stable releases are put, so currently 1.3 / 0.4, as you say).

The cuda library is provided in a separate package cudatoolkit of which you explicitly select version 9.2 on the command line.)

The end result is as you describe it

Best regards


Thanks for your reply.

According to your answer, there is a misunderstanding of cuda installation in my prior description. I thought cudatoolkit=9.2 means the installed pytorch is pre-compiled with cudatoolkit=9.2. However, it should be that it will install cudatoolkit 9.2. Base on this PyTorch Forum Discussion, it also means it will not only install a cudatoolkit, but also install a corresponding version of CuDNN.

So, my question is that,
Is this cudatoolkit and cuDNN installation in our conda environment solely or it is system-wide?