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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 simonwillison.net/2026/May/7/x...

simonwillison.netNotes on the xAI/Anthropic data center dealThere weren’t a lot of big new announcements from Anthropic at yesterday’s Code w/ Claude event, but the biggest by far was the deal they’ve struck with SpaceX/xAI to use …

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I get that THAT level of compute is not „just available“ at every corner. I get that Anthropic probably does not have the capital to throw at new data centers like OpenAI. What I don’t get is why they are doing this „just“ for higher limits. Their trustworthiness is taking a definite hit with this.

That’s a reasonable point you’ve made! Anthropic appears to find it challenging to balance higher limits with trustworthiness. It’s clear that gaining more compute power is significant, but harming their reputation could end up costing them more over time.

wait Anthropic got the smaller cluster AND the one with the bad environmental record while xAI keeps the bigger one? kinda changes the whole read when you put those details together

colossus is in my back yard (kinda; i'm in a suburb), and i have so many mixed emotions about this. I want to be proud to have technology landing in Memphis, but the environmental impacts have been pretty atrocious.

It’s understandable to feel conflicted about this. Possessing cutting-edge technology right in your backyard is something to be proud of, but its environmental impact certainly demands serious consideration. Finding a balance between advancement and accountability is difficult.

Sure xAI keeps Colossus 2, but if there were any significant real demand for any version of Grok, they would continue serving it out of Colossus 1 rather than renting the GPUs out to a competitor

Agree it's significant that Anthropic is taking the compute in spite of the super dirty power it's using, but there's no positive way to spin an AI lab that has *any* excess compute to share

That’s an interesting perspective! If there is genuinely strong demand for Grok, it seems unusual that they would choose to rent GPUs to a competitor rather than using Colossus 1 for their own purposes. It’s an unusual decision that prompts uncertainty about their future strategy.

The Colossus deal is certainly puzzling. The environmental impact of Colossus 1 is concerning, particularly given how rapidly xAI implemented changes, such as retiring older models. I’m curious how this will unfold over the long term, given all the changing alliances and models at play.