NCCL Release 2.12.7

This is the NCCL 2.12.7 release notes. For previous NCCL release notes, refer to the NCCL Archives.

Compatibility

NCCL 2.12.7 has been tested with the following:

Key Features and Enhancements

This NCCL release includes the following key features and enhancements.

  • Added NVLink-optimized network communication to keep traffic rail-local (PXN).

  • Improved alltoall latency by aggregating messages within a node to a given destination.

  • Added new v5 plugin API with grouped receives and tags, keeping compatibility for v4 plugins.

  • Added naming of NCCL threads to help debugging.

  • Added support for Relaxed Ordering for IB.

  • Added profiling and timing infrastructure.

Fixed Issues

The following issues have been resolved in NCCL 2.12.7:

  • Fixed NVLink detection and avoid data corruption when some NVLinks are down.