All frontier sites

Microsoft Fairwater Wisconsin

Microsoft
United States
Microsoft AI WAN
4800 90th St, Mount Pleasant, WI 53403
Current Power
555 MW
H100-equivalents
558,828
Capital Cost
$17.71B
Energy Provider
WE Energies

Site Location

Tenants / Users

OpenAI #likely, Microsoft #likely

Construction Timeline · 6 events

2023-07-142027-10-032027-10-03
Status
Building 4 operational. Based on how long Building 1 took from land clearing to operation.
Power (MW)
3328.0
IT Power (MW)
2774.0
H100-equiv
5,191,509
Cap-Ex ($B)
$106.25
Buildings Operational
4.0
Water (MGD)
0.02

Notes

Microsoft Fairwater Wisconsin is set to be the tech giant’s most powerful data center yet. The buildings have a two-story structure, with GPU racks networked vertically as well as horizontally. Each of these GPU buildings is paired with a one-story building dedicated to data storage and processing using CPUs. We estimated compute capacity based on disclosures from Microsoft, and permit applications showing the layout of server racks. Data on Building 3 and 4 is more uncertain, as it is based on the relative sizing of the buildings and mechanical areas in architectural drawings (see this [calculation](https://docs.google.com/spreadsheets/d/10bfo173cjvehaMqextiRGc95lBdPmtZbLDyNvbEN0N0/edit?gid=0#gid=0&range=B40)).

Sources

Calculations sheet
- [Microsoft blog with engineering details](https://blogs.microsoft.com/blog/2025/09/18/inside-the-worlds-most-powerful-ai-datacenter/) - [Microsoft blog with more general information](https://blogs.microsoft.com/on-the-issues/2025/09/18/made-in-wisconsin-the-worlds-most-powerful-ai-datacenter/) - [Construction Permit Application for building 1](https://drive.google.com/file/d/1azyXnreQBuYEqX2oaSUgePDGCMneez5Z/view?usp=sharing) - [Construction Permit Application for building 3 and 4 ](https://drive.google.com/file/d/1UXsNFoXCbstOK8upixx060-LFj8beHqp/view?usp=sharing)