diff --git a/cm3apps/install.txt b/cm3apps/install.txt
index f19eb4404303ae653ab08a9453976550f9b57fee..41516f33d0fc6454793e020cf973c65b8bb0cf41 100644
--- a/cm3apps/install.txt
+++ b/cm3apps/install.txt
@@ -492,12 +492,41 @@ C) Install Open Cascade (optional)
 D) Install Torch
         cd local
        // no gpu
-        wget https://download.pytorch.org/libtorch/cpu/libtorch-shared-with-deps-1.4.0%2Bcpu.zip
-        unzip libtorch-shared-with-deps-1.4.0+cpu.zip 
+          wget https://download.pytorch.org/libtorch/cpu/libtorch-shared-with-deps-1.4.0%2Bcpu.zip
+          unzip libtorch-shared-with-deps-1.4.0+cpu.zip 
        // gpu
-        sudo apt-get install nvidia-cuda-toolkit
-        //check version nvcc --version
-        wget https://download.pytorch.org/libtorch/cu101/libtorch-shared-with-deps-1.7.0%2Bcu101.zip
+           1) clean up
+           sudo rm /etc/apt/sources.list.d/cuda*
+           sudo apt remove --autoremove nvidia-cuda-toolkit
+           sudo apt remove --autoremove nvidia-*
+           2) purge
+           sudo apt-get purge nvidia*
+           sudo apt-get autoremove
+           sudo apt-get autoclean
+           sudo rm -rf /usr/local/cuda*
+           3) install graphics
+           sudo apt update
+           sudo add-apt-repository ppa:graphics-drivers
+           sudo apt-key adv --fetch-keys http://developer.download.nvidia.com/compute/cuda/repos/ubuntu2004/x86_64/7fa2af80.pub
+           sudo bash -c 'echo "deb http://developer.download.nvidia.com/compute/cuda/repos/ubuntu2004/x86_64 /" > /etc/apt/sources.list.d/cuda.list'
+           sudo bash -c 'echo "deb http://developer.download.nvidia.com/compute/machine-learning/repos/ubuntu2004/x86_64 /" > /etc/apt/sources.list.d/cuda_learn.list'
+           sudo apt update
+           sudo apt install cuda-11-0
+           sudo apt install libcudnn7
+           add in your .bashrc
+           export PATH=/usr/local/cuda/bin/:$PATH
+           export LD_LIBRARY_PATH=/usr/local/cuda/lib64/:$LD_LIBRARY_PATH
+           4) install cudnn 
+           download cudnn from nvidia (you need to register and downloadmanualy
+           https://developer.nvidia.com/compute/machine-learning/cudnn/secure/8.0.4/11.0_20200923/cudnn-11.0-linux-x64-v8.0.4.30.tgz
+           copy in your local directory
+           tar xvf cudnn-11.0-linux-x64-v8.0.4.30.tgz
+           sudo cp cuda/include/cudnn*.h /usr/local/cuda/include
+           sudo cp cuda/lib64/libcudnn* /usr/local/cuda/lib64
+           sudo chmod a+r /usr/local/cuda/include/cudnn*.h /usr/local/cuda/lib64/libcudnn*
+           5) download torch with gpu
+           wget https://download.pytorch.org/libtorch/cu110/libtorch-shared-with-deps-1.7.0%2Bcu110.zip
+           unzip libtorch-shared-with-deps-1.7.0%2Bcu110.zip
 
 
         add export TORCHDIR=$HOME/local/libtorch in your .bashrc