{"library":"nvidia-nccl-cu11","title":"NVIDIA Collective Communication Library (NCCL) Runtime for CUDA 11","description":"The `nvidia-nccl-cu11` package provides the NVIDIA Collective Communication Library (NCCL) runtime binaries specifically compiled for CUDA 11. NCCL is a high-performance library for collective communication operations (e.g., all-reduce, all-gather, broadcast) across multiple GPUs, both within a single node and across multiple nodes. It is optimized for NVIDIA GPUs and high-speed interconnects like NVLink and InfiniBand. This package primarily serves as a backend dependency for deep learning frameworks (like PyTorch, TensorFlow) and other GPU-accelerated libraries that require NCCL's capabilities for distributed computing. The current version is 2.21.5, with frequent updates corresponding to new NCCL releases and CUDA versions.","language":"python","status":"active","last_verified":"Fri May 15","install":{"commands":["pip install nvidia-nccl-cu11"],"cli":null},"imports":["import torch; torch.cuda.nccl.version()","from nccl.core import Communicator"],"auth":{"required":false,"env_vars":[]},"quickstart":{"code":"import torch\n\nif torch.cuda.is_available():\n    print(f\"CUDA available: {torch.cuda.is_available()}\")\n    print(f\"CUDA version: {torch.version.cuda}\")\n    if hasattr(torch.cuda, 'nccl'):\n        print(f\"NCCL version (via PyTorch): {torch.cuda.nccl.version()}\")\n    else:\n        print(\"PyTorch's CUDA backend does not expose NCCL version directly, or NCCL not linked.\")\nelse:\n    print(\"CUDA is not available. NCCL requires NVIDIA GPUs and CUDA.\")\n","lang":"python","description":"This quickstart demonstrates how to verify that NCCL is detected and its version reported by a common deep learning framework like PyTorch. The `nvidia-nccl-cu11` package provides the backend, and frameworks then expose its capabilities. This code checks for CUDA availability and attempts to retrieve the NCCL version via PyTorch's API, which is a common way users confirm NCCL's presence and compatibility.","tag":null,"tag_description":null,"last_tested":null,"results":[]},"compatibility":{"tag":null,"tag_description":null,"last_tested":"2026-05-15","installed_version":"2.21.5","pypi_latest":"2.21.5","is_stale":false,"summary":{"python_range":"3.10–3.9","success_rate":50,"avg_install_s":4.2,"avg_import_s":null,"wheel_type":"wheel"},"results":[{"runtime":"python:3.10-alpine","python_version":"3.10","os_libc":"alpine (musl)","variant":"nvidia-nccl-cu11","exit_code":1,"wheel_type":null,"failure_reason":"build_error","import_side_effects":null,"install_time_s":null,"import_time_s":null,"mem_mb":null,"disk_size":null},{"runtime":"python:3.10-slim","python_version":"3.10","os_libc":"slim (glibc)","variant":"nvidia-nccl-cu11","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"broken","install_time_s":4.5,"import_time_s":null,"mem_mb":null,"disk_size":"202M"},{"runtime":"python:3.11-alpine","python_version":"3.11","os_libc":"alpine (musl)","variant":"nvidia-nccl-cu11","exit_code":1,"wheel_type":null,"failure_reason":"build_error","import_side_effects":null,"install_time_s":null,"import_time_s":null,"mem_mb":null,"disk_size":null},{"runtime":"python:3.11-slim","python_version":"3.11","os_libc":"slim (glibc)","variant":"nvidia-nccl-cu11","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"broken","install_time_s":4.1,"import_time_s":null,"mem_mb":null,"disk_size":"204M"},{"runtime":"python:3.12-alpine","python_version":"3.12","os_libc":"alpine (musl)","variant":"nvidia-nccl-cu11","exit_code":1,"wheel_type":null,"failure_reason":"build_error","import_side_effects":null,"install_time_s":null,"import_time_s":null,"mem_mb":null,"disk_size":null},{"runtime":"python:3.12-slim","python_version":"3.12","os_libc":"slim (glibc)","variant":"nvidia-nccl-cu11","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"broken","install_time_s":4.2,"import_time_s":null,"mem_mb":null,"disk_size":"196M"},{"runtime":"python:3.13-alpine","python_version":"3.13","os_libc":"alpine (musl)","variant":"nvidia-nccl-cu11","exit_code":1,"wheel_type":null,"failure_reason":"build_error","import_side_effects":null,"install_time_s":null,"import_time_s":null,"mem_mb":null,"disk_size":null},{"runtime":"python:3.13-slim","python_version":"3.13","os_libc":"slim (glibc)","variant":"nvidia-nccl-cu11","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"broken","install_time_s":3.7,"import_time_s":null,"mem_mb":null,"disk_size":"195M"},{"runtime":"python:3.9-alpine","python_version":"3.9","os_libc":"alpine (musl)","variant":"nvidia-nccl-cu11","exit_code":1,"wheel_type":null,"failure_reason":"build_error","import_side_effects":null,"install_time_s":null,"import_time_s":null,"mem_mb":null,"disk_size":null},{"runtime":"python:3.9-slim","python_version":"3.9","os_libc":"slim (glibc)","variant":"nvidia-nccl-cu11","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"broken","install_time_s":4.6,"import_time_s":null,"mem_mb":null,"disk_size":"201M"}]}}