Skip to content

NCCL: NVIDIA Collective Communication Library

Overview of package

Package: NCCL
Description: NVIDIA Collective Communication Library
For more information: https://developer.nvidia.com/cuda-zone
Categories: SoftwareDevelopment
License: Unknown

General Usage

NCCL is a library providing inter-GPU communication primitives that are topology-aware and can be easily integrated into applications.

NCCL provides both collective communication and point-to-point send/receive primitives. It is not a full-blown parallel programming framework but rather a library focused on accelerating inter-GPU communication.

The following environmental variables have been defined:

  • $NCCL_ROOT has been set to the root of the nccl installation
  • $NCCL_LIBDIR points to the directory containing the libraries
  • $NCCL_INCDIR points to the directory containing the header files

You will probably wish to use these by adding the following flags to your compilation command (e.g. to CFLAGS in your Makefile):

  • -I$NCCL_INCDIR

and the following flags to your link command (e.g. LDFLAGS in your Makefile):

  • -L$NCCL_LIBDIR -Wl,-rpath,$NCCL_LIBDIR

Available versions by cluster

This section lists the available versions of the package NCCLon the UMD HPC clusters.

Versions available on the Zaratan cluster

Version Module tags CPU(s) optimized for GPU ready?
2.11.4-1 2.11.4-1 zen2 Yes
2.18.1-1 2.18.1-1 icelake, zen2 Yes