Musk's Colossus 1 AI supercomputer's inefficient mixed-architecture design couldn't be used to train Grok, so Anthropic's using it for inference instead — Musk readies unified Blackwell-only Colossus 2 for frontier training and potential IPO

Anthropic has leased xAI’s entire 220,000-GPU Colossus 1 supercluster from SpaceX to ease Claude’s growing compute bottlenecks, in a deal that may reveal far bigger ambitions around AI infrastructure, orbital data centers, and Musk’s IPO strategy.