- Overview
The NVIDIA® Collective Communications Library ™ (NCCL) (pronounced “Nickel”) is a library
of multi-GPU collective communication primitives that are topology-aware
and can be easily integrated into applications.
- Prerequisites
2.1. Software Requirements
Ensure your environment meets the following software requirements:
glibc 2.19 or higher
CUDA 8.0 or higher
2.2. Hardware Requirements
NCCL supports all CUDA devices with a compute capability of 3.0 and higher. For the compute capability of all NVIDIA GPUs, check: CUDA GPUs.
- Installing NCCL
In order to download NCCL, ensure you are registered for the NVIDIA Developer Program.
Go to: NVIDIA NCCL home page. (https://developer.nvidia.com/nccl\)
Click Download.
Complete the short survey and click Submit.
Accept the Terms and Conditions. A list of available download versions of NCCL displays.
Select the NCCL version you want to install. A list of available resources displays. Refer to the following sections to choose the correct package depending on the Linux distribution you are using.
3.1. Ubuntu 14.04 LTS And Ubuntu 16.04 LTS
Installing NCCL on Ubuntu requires you to first add a repository to the APT system containing the NCCL packages, then installing the NCCL packages through APT. There are two repositories available; a local repository and a network repository. Choosing the later is recommended to easily retrieve upgrades when newer versions are posted.
Install the repository.
For the local NCCL repository:
# dpkg -i nccl-repo-ubuntu1604-2.1.2-ga-cuda9.0_1-1_amd64.deb
Update the APT database:
# apt update
Note: Ensure you prefix the commands with sudo if they are not run as root.
Install the libnccl2 package with APT. Additionally, if you need to compile applications with NCCL, you can install the libnccl-dev package:
# apt install libnccl2 libnccl-dev