Simon Willison· Updated
Simon Willison highlighted that Anthropic's lease of the Colossus 1 data center includes a kill switch allowing xAI to reclaim compute at will. The analysis also reveals that xAI is retaining its superior Colossus 2 facility while abruptly deprecating older models to make room for the partnership. This shift exposes significant supply chain risks for Anthropic and highlights the environmental cost of the Memphis-based infrastructure.
grok-4-1-fast, with only two weeks' notice to clear capacity for the new tenant.His analysis highlights a massive supply chain risk: Elon Musk explicitly reserved the right to reclaim the compute if he decides the AI "harms humanity." This creates a precarious dependency for Anthropic on a direct competitor. Furthermore, Colossus 1 has a history of environmental violations, including running gas turbines without permits, which Willison describes as a significant reputational liability.
Willison's analysis surfaces how front-tier AI labs are accepting increasingly volatile infrastructure tradeoffs. The sudden deprecation of the grok-4-1 series serves as a warning about platform stability when compute providers are also competitors. His reporting frames this as an emerging pattern — frontier labs prioritizing raw compute access over vendor stability.
Under-reported details of the xAI/Anthropic Colossus data center deal: Anthropic get Colossus 1 but xAI keep using the larger Colossus 2, Colossus 1 has a REALLY bad environmental record, and xAI just shut down a bunch of older models on 2 weeks' notice https://t.co/oCKBRNwPVH
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