AI Cyberspace

Nov 19, 2025 · Artificial Intelligence

Why MPI and NCCL Are Critical for Scaling AI Models Across Thousands of GPUs

This article explains how AI model training has evolved from single‑GPU workloads to massive distributed training using MPI for CPU‑centric communication and NCCL for GPU‑centric communication, covering their histories, core concepts, programming interfaces, topology discovery, protocol choices, and performance testing on multi‑GPU clusters.