NVIDIA/nccl-tests

Health v2 · maintenance only

Flags: no_releases

Adoption not part of the score

1636 stars · 399 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded

NVIDIA's official test suite for NCCL that measures the performance and correctness of collective communication operations across GPUs. It supports single- and multi-node runs via MPI and reports bandwidth metrics like busbw.

Use cases

• benchmark allreduce bandwidth across multiple GPUs
• verify NCCL collective operations are correct
• measure multi-node GPU communication performance
• profile bus bandwidth for distributed training clusters
• test NCCL performance from 8 bytes to gigabyte message sizes
• validate GPU interconnect performance after cluster setup

When to choose

• you need to benchmark or validate NCCL collective operations on NVIDIA GPUs
• you are tuning or validating multi-node GPU clusters for distributed training
• you want official, well-maintained NCCL performance baselines

When to avoid

• you need to benchmark non-NVIDIA GPU communication libraries
• you want a general-purpose GPU compute benchmark rather than communication tests
• your environment has no CUDA/NCCL installation

Facets

cli-tool · maturity active

benchmarking testing gpu-computing developer-tools performance gpu-computing cli nccl cuda mpi multi-node collective-communication hpc linux

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markdown · JSON · MCP: product_card(name="NVIDIA/nccl-tests")