NVIDIA Deep Learning NCCL Documentation
Release Notes (PDF) - v2.21.5 - Last updated June 18, 2024

NCCL Release 2.10.3

This is the NCCL 2.10.3 release notes. For previous NCCL release notes, refer to the NCCL Archives.


NCCL 2.10.3 has been tested with the following:

Key Features and Enhancements

This NCCL release includes the following key features and enhancements.

  • Added ncclAvg operation

  • Added support for bfloat16 type

  • Added support for multiple IB queue pairs

  • Added WSL2 support (single GPU only)

  • Improved performance for aggregation

  • Improved performance for medium sizes

  • Improved network error reporting

  • Added NCCL_NET environment variable to use a specific network

  • Added auto-load of XML topology from default location

Fixed Issues

The following issues have been resolved in NCCL 2.10.3:
  • Fixed graph search on cubemesh topologies.

  • Fixed all-to-all affinity to improve latency.

  • Fixed hang in cubemesh NVB connections during initialization.