Meta Opens Up Prometheus, the Ohio Supercluster It Plans to Scale to About 1 Million GPUs

Meta has published a detailed look at Prometheus, its gigawatt-scale AI supercluster in New Albany, Ohio. The post went up on Meta’s engineering blog on October 19, 2026, following the release of Meta’s Muse family of models.

What it is

Meta says the first phase of Prometheus is complete and was used to train the Muse foundation models, including Muse Wonder. Today the cluster comprises hundreds of thousands of GPUs spread across multiple interconnected buildings, including traditional and AI-optimized data centers and rapid-deployment structures, all working as a single machine. At full scale, Meta expects Prometheus to reach roughly 1 million GPUs.

Two years ago, Meta says, New Albany was a conventional data center site running web traffic. The company reworked it for frontier-model training and is now scaling it further with the next models from Meta Superintelligence Labs in mind.

Keeping one giant job running

On large training runs, a problem on a single host can slow or stop the whole job, which lowers what Meta calls goodput, the share of time spent on useful training.

• Muse Wonder pre-training runs achieved more than 85% goodput.
• Its reinforcement learning runs achieved more than 90%.
• The overall wall-clock mean time between interruptions was about 47,000 GPU hours during those runs, and Meta says firmware and other fleet fixes have since pushed it above 54,000 GPU hours.

The hardware

Prometheus currently runs two NVIDIA platforms, with a third, based on NVIDIA Vera Rubin NVL72, arriving soon.

• Catalina uses the NVIDIA GB200 NVL72 in a two-rack layout: 72 Blackwell GPUs with 13.4 TB of HBM3e, 720 peak PFLOPS of FP8 training compute and about 120 kW across the pair. Meta paired each GPU with 800G of network I/O.
• Clemente uses the NVIDIA GB300 NVL72, fitting all 72 GPUs in a single rack with 288 GB of memory per GPU (1.5 times the GB200), about 135 kW of rack power and a 5 to 10% performance gain over the GB200 version.

Inside each building, an Ethernet fabric connects up to 20,736 GPUs, and an aggregation network links the buildings together. Meta also uses closed-loop liquid cooling to handle the heat from its dense GPU racks.

All of the figures above come from Meta’s own engineering post.