US company NVIDIA has unveiled the Rubin generation AI infrastructure, which for the first time in the world uses fully liquid cooling in a closed loop without fans. The new servers can operate with a coolant temperature of up to 45 °C, which significantly improves data center energy efficiency compared with traditional recommendations to maintain ambient temperature in the 18–27 °C range.
In the NVIDIA DSX reference design for AI factories, water consumption is completely eliminated. As noted by the director of cooling and data center infrastructure Ali Heydari, the system is built on dry cooling towers and operates in a closed loop, using chillers only in rare cases in certain climate zones—no more than 1% of the time per year.
Cooling traditionally consumes up to 40% of a data center’s electricity, and each degree of increase in chiller plant temperature reduces costs by about 4%. Switching to liquid cooling delivers a hyperscale facility with a capacity of 50 MW savings of more than $4 million per year on energy and water.
Key details of the cooling system 💧
- The coolant is a mixture of 75% water and 25% propylene glycol.
- The mixture circulates through cold plates directly on the processors.
- This architecture:
- reduces water use to zero;
- enables waste heat recovery ♻️.