Microsoft unveils Fairwater, its AI data centre in Wisconsin

2025-09-18 · Publisher : Microsoft · Domain : Cloud & DevOps

Microsoft introduces Fairwater in Mount Pleasant, Wisconsin, a 315-acre AI campus designed as a single supercomputer of hundreds of thousands of NVIDIA GPUs, with closed-loop liquid cooling.

### Background On 18 September 2025, Microsoft introduces **Fairwater**, its new AI data centre in Mount Pleasant, Wisconsin, which it calls the largest and most sophisticated of its "AI factories". The site spans 315 acres and three buildings totaling 1.2 million square feet. It works as a single supercomputer, with a flat network linking hundreds of thousands of NVIDIA GPUs. Microsoft claims ten times the performance of today's fastest supercomputer and says other identical Fairwater sites are under construction in the United States. ### Key facts - Size: 315 acres, three buildings, 1.2 million square feet under roof. - Compute: hundreds of thousands of the latest NVIDIA GPUs, including GB200, in one flat network, with racks linked across two levels. - Cooling: closed-loop liquid, filled once then reused, with the world's second-largest water-cooled chiller plant, according to Microsoft. - AI wide area network (AI WAN): several Azure data centres linked to form a distributed supercomputer. - Other sites cited: Narvik (Norway) with nScale and Aker, Loughton (UK) with nScale. ### Why it matters Microsoft changes its infrastructure model: a data centre designed for a single purpose, training and inference of giant models, rather than a general-purpose room. For customers, this capacity first serves OpenAI, Microsoft AI and Copilot, with future availability for other workloads. The performance figures are Microsoft's and depend on the measures chosen. ### Takeaway The AI data centre becomes a single machine, designed around the network and liquid cooling.

Tags : Datacenter, Azure, Refroidissement liquide, NVIDIA, États-Unis