NEWS

Meta Reveals How Prometheus Will Scale to 1 Million GPUs

Long aisle of server racks with dense yellow fiber cabling inside a Meta AI data center
Server racks inside Meta's AI data center infrastructure. Source: Engineering at Meta
Quick answer: Prometheus is Meta's gigawatt-scale AI supercluster in New Albany, Ohio. In an October 19, 2026 engineering post, Meta said its completed first phase links hundreds of thousands of Nvidia GPUs and trained the Muse Wonder models with more than 85% goodput in pre-training and more than 90% in reinforcement learning, and that the cluster is being scaled toward roughly 1 million GPUs.
TLDR

Meta has published the first detailed engineering account of Prometheus, its gigawatt-scale AI supercluster in New Albany, Ohio, confirming that the completed first phase trained its Muse Wonder frontier models and that the company is now scaling the site toward roughly 1 million GPUs. The post from Meta's infrastructure team says the cluster already links hundreds of thousands of Nvidia GPUs across multiple buildings, some up to 100 km apart, so that they run as a single machine.

Prometheus trained Muse Wonder on hundreds of thousands of Nvidia GPUs

Two years ago the New Albany campus served ordinary web traffic. Meta rebuilt it in phases, mixing conventional data halls, AI-optimized buildings and rapid-deployment structures, and stitched them together with what it describes as millions of miles of fiber strand and tens of thousands of switches. Each building-level Ethernet fabric connects up to 20,736 GPUs, and an aggregation network joins those fabrics across distances from 2 km to more than 100 km.

The hardware spans three Nvidia generations. Catalina racks use the GB200 NVL72, Clemente racks use the GB300 NVL72 with 288 GB of memory per GPU, and a third platform, San Miguel, will bring Vera Rubin NVL72 racks drawing more than 170 kW each.

PlatformNvidia systemMemory per GPURack power
CatalinaGB200 NVL72192 GB HBM3e~120 kW (two-rack pair)
ClementeGB300 NVL72288 GB HBM3e~135 kW
San MiguelVera Rubin NVL72288 GB HBM4170 kW+

Source: Engineering at Meta, October 19, 2026.

Reliability, measured in GPU hours, is the real engineering result

The most useful numbers in Meta's account concern failure. A 72-GPU rack shares one high-bandwidth domain, which Meta says enlarges the blast radius of a single fault ninefold compared with the eight-GPU servers of the H100 era. Meta answers that by running each rack as a 64-GPU slice with eight in-rack spares and holding about 2% extra racks in reserve. For a training run that needs 32,768 active GPUs, it provisions 37,656, so roughly 4,900 GPUs, about 13% of the footprint, sit ready as spares.

Log-scale bar chart showing Meta Prometheus training interruptions per 8,000 GPUs per day falling from about 1,000 in mid-2025 to about 3.6 after firmware fixes, against a target of 2
Interruptions per 8,000 GPUs per day fell from about 1,000 at the mid-2025 peak to about 3.6 today, against Meta's target of 2. Chart: Santage. Source: Engineering at Meta, October 19, 2026; middle values calculated by Santage from Meta's MTBI figures.

Meta reports a mean time between interruptions of about 47,000 GPU hours during the Muse Wonder runs and more than 54,000 GPU hours after later firmware fixes, with a stated goal of about 100,000. The company credits a co-engineering arrangement with Nvidia, whose teams work on site at New Albany and share telemetry for joint triage of every halt.

Meta keeps about one GPU in eight on standby for its largest training runs, a reminder that the cost of frontier AI infrastructure now includes a large reserve of hardware bought specifically to sit idle until something breaks.

The disclosure follows Meta's release of Muse Spark Open and its push into in-house silicon, and it gives the clearest view yet of the AI infrastructure behind those models. Prometheus shows that Meta's frontier ambitions now rest as much on keeping hundreds of thousands of GPUs running in lockstep as on the models themselves, and the 99% cut in interruptions is the figure that explains how the Muse Wonder runs finished at all.

Santage is committed to independent, transparent journalism. This article is produced in accordance with Santage's Editorial Standards and aims to provide accurate and timely information. Readers are encouraged to verify information independently.