Open the terminal and remove any NVIDIA traces that you may have on your system.

sudo rm /etc/apt/sources.list.d/cuda*

sudo apt remove --autoremove nvidia-cuda-toolkit

sudo apt-get remove --autoremove nvidia-*

Setup the correct CUDA PPA on your system.

export DISTRO=ubuntu2004

export ARCHITECTURE=x86_64

sudo apt update

sudo add-apt-repository ppa:graphics-drivers

sudo apt-key adv --fetch-keys https://developer.download.nvidia.com/compute/cuda/repos/${DISTRO}/${ARCHITECTURE}/7fa2af80.pub 

sudo bash -c "echo deb http://developer.download.nvidia.com/compute/cuda/repos/${DISTRO}/${ARCHITECTURE}/ / > /etc/apt/sources.list.d/cuda.list"  

sudo bash -c "echo deb http://developer.download.nvidia.com/compute/machine-learning/repos/${DISTRO}/${ARCHITECTURE} / > /etc/apt/sources.list.d/cuda_learn.list"  

Install CUDA 11.1 packages.

sudo apt update

sudo apt -y install cuda-11-1

sudo apt install libcudnn8

Specify the PATH to CUDA in the '.profile' file. Open the file by running sudo nano ~/.profile and add the following lines at the end of the file:

# set PATH for cuda 11.1 installation

if [ -d "/usr/local/cuda-11.1/bin/" ]; then

    export PATH=/usr/local/cuda-11.1/bin${PATH:+:${PATH}}

    export LD_LIBRARY_PATH=/usr/local/cuda-11.1/lib64${LD_LIBRARY_PATH:+:${LD_LIBRARY_PATH}}

fi

Use the keyboard combination Ctrl + O and after that press Enter to save the file to its current location. Use the keyboard combination Ctrl + X to exit nano.

Restart with sudo reboot and check the versions of the installation.

CUDA:

nvcc  --version

NVIDIA driver:

nvidia-smi

libcudnn:

/sbin/ldconfig -N -v $(sed ‘s/:/ /’ <<< $LD_LIBRARY_PATH) 2>/dev/null | grep libcudnn