Meta details gigawatt-scale Prometheus supercluster; first phase is training Muse models

Meta says the first phase of its gigawatt-scale Prometheus supercluster is complete and is being used to train the Muse model family. It has hundreds of thousands of GPUs now, with plans to reach about 1 million. Effective throughput tops 85% for Muse Wonder pretraining and 90% for RL training, and a year of engineering work cut cluster interruptions 99% from their peak.

Why it matters: Meta combines in-rack spare GPUs, parallelism-aware fault tolerance and asynchronous checkpointing into a practical method for cutting downtime and repeated compute in large training runs.