NVIDIA Deep Learning NCCL Documentation
Release Notes (PDF) - v2.21.5 - Last updated April 5, 2024

NCCL Release 2.16.2

This is the NCCL 2.16.2 release notes. For previous NCCL release notes, refer to the NCCL Archives.


NCCL 2.16.2 has been tested with the following:

Key Features and Enhancements

This NCCL release includes the following key features and enhancements.

  • Add support for CUDA 12.0

  • Make socket support more resistant to network scanners

  • Improve performance on large CUDA graphs, reducing dependencies

  • Compile with profiling API by default

  • Extend NVTX instrumentation with call arguments

Fixed Issues

The following issues have been resolved in NCCL 2.16.2:

  • Various fixes to ncclCommAbort

  • Make service thread polling resistant to EINTR

  • Adjust inter-socket AMD bandwidth model to favor faster paths

Updating the GPG Repository Key

To best ensure the security and reliability of our RPM and Debian package repositories, NVIDIA is updating and rotating the signing keys used by apt, dnf/yum, and zypper package managers beginning on April 27, 2022. Failure to update your repository signing keys will result in package management errors when attempting to access or install NCCL packages. To ensure continued access to the latest NCCL release, please follow the updated NCCL installation guide.