Introduction

Introduction#

Note

This document describes the legacy C++ API. Documentation for the new C API that closely follows the NVIDIA Collective Communications Library (NCCL)* API standard can be found here.

The existing C++ API will remain the default API for the 2021.17 release.

oneAPI Collective Communications Library (oneCCL) (oneCCL) provides an efficient implementation of communication patterns used in deep learning.

oneCCL features include:

  • Built on top of lower-level communication middleware – Intel® MPI Library and libfabrics.

  • Optimized to drive scalability of communication patterns. It supports collectives and point-to-point (send/receive) primitives.

  • Works across various interconnects: InfiniBand*, Cornelis Networks*, and Ethernet.

  • Provides common API sufficient to support communication workflows within Deep Learning / distributed frameworks (such as PyTorch*, Horovod*).

oneCCL package comprises the oneCCL Software Development Kit (SDK) and the Intel® MPI Library Runtime components.