IREN Starts First Phase of $9.7 Billion Microsoft AI Deal, Accelerating Shift From Bitcoin Mining

IREN, which is expanding from Bitcoin mining into AI infrastructure, has completed the first AI cloud deployment under its $9.7 billion contract with Microsoft.

The Block reported on Aug. 17 that IREN completed the 50-megawatt Horizon 1 build-out at its data center in Childress, Texas, and began supplying capacity to Microsoft. It is the first delivery under the five-year, $9.7 billion cloud services agreement the companies signed in November 2025.

Under the contract, IREN will build AI cloud infrastructure in four phases, from Horizon 1 through Horizon 4. The full project will provide 200 megawatts of IT capacity and use Nvidia GB300 graphics processing units. Horizon 2 through Horizon 4 are scheduled to be delivered in stages within 2026.

Horizon 1 uses a liquid-cooling system that directly cools GPUs. IREN also said Horizon 1 has been designated an Nvidia Exemplar Cloud in recognition of its performance and reliability in handling AI workloads.

IREN is also increasing investment in AI infrastructure tied to the Microsoft contract. In June, it raised $3.65 billion in debt financing to fund GPU purchases and related spending. At the time, the company said the financing could cover about 96% of the total $5.81 billion GPU investment linked to the Microsoft agreement.

The company is rapidly shifting its focus from Bitcoin mining, once its core business, to AI and high-performance computing infrastructure. It plans to expand AI cloud capacity to 480 megawatts this year and to 1.2 gigawatts by 2027.

"Horizon 1 demonstrates the strength of our vertically integrated business model and our ability to deliver complex AI infrastructure projects quickly and at scale," Daniel Roberts, IREN's co-founder and co-chief executive officer, said.