linuxubuntucudacudatoolkit

nvcc version remains the same after updating the CUDA Toolkit version


I installed CUDA Toolkit 12.6 Update 1 in Ubuntu 22.04 using the command below (instructions are found here):

wget https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2204/x86_64/cuda-ubuntu2204.pin
sudo mv cuda-ubuntu2204.pin /etc/apt/preferences.d/cuda-repository-pin-600
wget https://developer.download.nvidia.com/compute/cuda/12.6.1/local_installers/cuda-repo-ubuntu2204-12-6-local_12.6.1-560.35.03-1_amd64.deb
sudo dpkg -i cuda-repo-ubuntu2204-12-6-local_12.6.1-560.35.03-1_amd64.deb
sudo cp /var/cuda-repo-ubuntu2204-12-6-local/cuda-*-keyring.gpg /usr/share/keyrings/
sudo apt-get update
sudo apt-get -y install cuda-toolkit-12-6

The installation is successful. However, the nvcc version is still 11.5. Here are 2 packages I installed. I thought installing the CUDA Toolkit 12.6 would replace 11.5, but the NVCC still comes from 11.5.

$ dpkg -l nvidia-cuda-toolkit
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name                Version         Architecture Description
+++-===================-===============-============-=================================
ii  nvidia-cuda-toolkit 11.5.1-1ubuntu1 amd64        NVIDIA CUDA development toolkit

$ dpkg -l cuda-toolkit-12-6
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name              Version      Architecture Description
+++-=================-============-============-=================================
ii  cuda-toolkit-12-6 12.6.1-1     amd64        CUDA Toolkit 12.6 meta-package

How can I update the nvcc version to 12.6?


Here is the output of nvcc -V:

$ nvcc -V
nvcc: NVIDIA (R) Cuda compiler driver
Copyright (c) 2005-2021 NVIDIA Corporation
Built on Thu_Nov_18_09:45:30_PST_2021
Cuda compilation tools, release 11.5, V11.5.119
Build cuda_11.5.r11.5/compiler.30672275_0

Listing out the contents of the cuda-toolkit-12-6, it does not include the nvcc:

$ dpkg -L cuda-toolkit-12-6
/.
/usr
/usr/local
/usr/local/cuda-12.6
/usr/local/cuda-12.6/version.json
/usr/share
/usr/share/doc
/usr/share/doc/cuda-toolkit-12-6
/usr/share/doc/cuda-toolkit-12-6/changelog.Debian.gz

Output of nvidia-smi:

$ nvidia-smi
Mon Sep 23 13:11:55 2024       
+---------------------------------------------------------------------------------------+
| NVIDIA-SMI 535.183.01             Driver Version: 535.183.01   CUDA Version: 12.2     |
|-----------------------------------------+----------------------+----------------------+
| GPU  Name                 Persistence-M | Bus-Id        Disp.A | Volatile Uncorr. ECC |
| Fan  Temp   Perf          Pwr:Usage/Cap |         Memory-Usage | GPU-Util  Compute M. |
|                                         |                      |               MIG M. |
|=========================================+======================+======================|
|   0  NVIDIA GeForce RTX 4090        Off | 00000000:81:00.0 Off |                  Off |
|  0%   24C    P8              21W / 450W |  10893MiB / 24564MiB |      0%      Default |
|                                         |                      |                  N/A |
+-----------------------------------------+----------------------+----------------------+
|   1  NVIDIA GeForce RTX 4090        Off | 00000000:C1:00.0 Off |                  Off |
|  0%   24C    P8              32W / 450W |    818MiB / 24564MiB |      0%      Default |
|                                         |                      |                  N/A |
+-----------------------------------------+----------------------+----------------------+
                                                                                         
+---------------------------------------------------------------------------------------+
| Processes:                                                                            |
|  GPU   GI   CI        PID   Type   Process name                            GPU Memory |
|        ID   ID                                                             Usage      |
|=======================================================================================|
|    0   N/A  N/A      1720      G   /usr/lib/xorg/Xorg                            4MiB |
|    0   N/A  N/A      2174      C   /usr/local/bin/ollama                       384MiB |
|    0   N/A  N/A   1808406      C   /opt/tljh/user/bin/python                 10486MiB |
|    1   N/A  N/A      1720      G   /usr/lib/xorg/Xorg                           15MiB |
|    1   N/A  N/A      1896      G   /usr/bin/gnome-shell                         10MiB |
|    1   N/A  N/A      2174      C   /usr/local/bin/ollama                       384MiB |
|    1   N/A  N/A   1808406      C   /opt/tljh/user/bin/python                   386MiB |
+---------------------------------------------------------------------------------------+

Solution

  • You should check your environment variables. It’s possible that nvcc is still pointing to CUDA 11.5 because your PATH and LD_LIBRARY_PATH are set to the old version.

    To fix this, update your environment variables by adding the following lines to your .bashrc (or .zshrc):

    export PATH=/usr/local/cuda-12.6/bin${PATH:+:${PATH}}
    export LD_LIBRARY_PATH=/usr/local/cuda-12.6/lib64${LD_LIBRARY_PATH:+:${LD_LIBRARY_PATH}}
    export CUDA_HOME=/usr/local/cuda-12.6
    

    Then, source the file:

    source ~/.bashrc
    

    This should make nvcc point to the correct CUDA version.

    or create a symbolic link pointing to your new CUDA version.