• Horizon 1 uses direct-to-chip liquid cooling and NVIDIA GB300 NVL72 systems and has been accepted by Microsoft, with the deployment also receiving NVIDIA Exemplar Cloud status
  • Three more 50MW buildings remain scheduled for delivery to Microsoft in 2026 under IREN's five-year, $9.7bn cloud-services contract

The fact

IREN said Microsoft has accepted Horizon 1, a 50MW IT-load AI-cloud building at the company's Childress campus in Texas. The direct-to-chip liquid-cooled facility is the first of four 50MW deployments scheduled for Microsoft during 2026 under a five-year cloud-services contract valued at about $9.7bn.

NVIDIA tested IREN's GB300 NVL72 deployment at Horizon 1 and awarded it Exemplar Cloud status. When the Microsoft agreement was announced in November 2025, IREN said the four phases would provide a combined 200MW of critical IT load and that Microsoft would make a 20% prepayment. Horizons 2, 3 and 4 remain scheduled for delivery later in 2026. IREN has not disclosed when Horizon 1 will begin contributing to reported AI-cloud revenue.

The assessment

Microsoft's acceptance of Horizon 1 moves IREN past the first handover, but it also makes the remaining task clearer. IREN now has another 150MW across three buildings to take through the same process during 2026. That means finishing the buildings is not enough. Power, liquid cooling, networking and the GPU systems all have to be commissioned to the point where Microsoft accepts the capacity. Horizon 1 shows that IREN has completed that sequence once at Childress. It does not show that the remaining buildings will reach acceptance on the same timetable.

IREN has not said when Horizon 1 starts contributing to AI-cloud revenue, so the acceptance date alone does not show when the contract begins to affect reported results. For BTW readers, the more useful test is whether Horizons 2, 3 and 4 reach Microsoft on schedule, and whether the time between completion and acceptance stays consistent as IREN works through the remaining 150MW.

What to watch

Watch the completion and Microsoft acceptance dates for Horizons 2, 3 and 4. Installed GPU counts, commissioning updates and any disclosure on when accepted capacity begins contributing to AI-cloud revenue will show whether the remaining 150MW is moving through the same handover process as Horizon