NVIDIA has revealed that its newest AI data centre hardware is cooled using water heated to around 45°C (113°F), warmer than a typical hot tub, as part of a shift away from traditional air-chilled server rooms. Although it sounds counterintuitive, running coolant at higher temperatures allows outdoor dry coolers to shed heat naturally without energy-hungry mechanical chillers, cutting both electricity and water use significantly at a time when AI infrastructure's environmental footprint is under growing scrutiny.

The new Rubin generation of NVIDIA's AI servers is fully liquid-cooled, eliminating fans and cold aisles in favour of a closed-loop system. Since cooling has historically accounted for up to 40% of a data centre's electricity bill, and each one-degree rise in chiller temperature can cut cooling costs by roughly 4%, the savings at scale are substantial, an estimated $4 million (£3.1m) a year for a 50-megawatt facility. Water use also falls dramatically, from around 2.6 million gallons per megawatt annually with conventional cooling towers to nearly zero. The redesigned servers are quieter and more compact too, with equipment that once filled six rack units now fitting into two.