TL;DRSpaceX rented Colossus 1 to Anthropic after hitting latency and chip mismatch issues trying to use it for Grok. The newer facilities use uniform Blackwell chips.
SpaceX rented its Colossus 1 data centre to Anthropic not because it had surplus capacity, but because it could not make the facility work for its own AI models. Bloomberg reported on Friday that SpaceX encountered latency issues when trying to connect the Memphis site to two other data centre campuses located more than 10 miles away, compounded by aging network infrastructure.
The company had planned to train its most cutting-edge Grok models using a cluster of three facilities working together. Training large AI models requires ultra-fast connections between sites. If the links are older or lower bandwidth, they create delays that slow the entire cluster. SpaceX determined the facility would be more valuable generating revenue than sitting underutilised.
The hardware mismatch made things worse. Colossus 1 contains a mix of Nvidia chip generations, including Hopper and Blackwell systems alongside older accelerators. Colossus 2 and 3 were built more uniformly around Nvidia’s Blackwell chips. In a distributed training cluster, the workload is spread across machines that need to stay synchronised. Older chips create bottlenecks by forcing faster accelerators to wait. The cluster ends up performing closer to its slowest hardware, not its fastest.
