This is the steps to install pytorch on an Ubuntu 20.04 machine with Nvidia Geforce RTX 3090 graphics card.

• First, turn off Secure Boot in BIOS or other boot menu. Secure boot will cause

  the driver not work.

• detect the graphics card with the built-in command

  > nvidia-detect

  > nvidia-driver-470

• install the graphics driver

  > sudo apt install nvidia-driver-470

  **Note it is not necessary to install `nvidia-cuda-toolkit` since it will be install via conda**

• install pytorch via the command provided by https://pytorch.org/get-started/locally/

  **Note the version 11.1 must be explicitly specified**

  > conda install pytorch torchvision torchaudio cudatoolkit=11.1 -c pytorch -c nvidia

It shall work now. run some examples and watch the nvidia-smi