Largest cluster on custom (non-GPU) AI silicon

AWS (Project Rainier) / Anthropic — AWS activated Project Rainier — nearly 500,000 of its own Trainium2 chips across multiple US data centers, one of the world's largest AI compute clusters and the biggest built on custom silicon rather than Nvidia GPUs. Anthropic trains and serves Claude on it (>5x its previous training compute), scaling toward 1M+ Trainium2 chips — a proof point that frontier-scale compute can run on a hyperscaler's in-house accelerators.