Nvidia Rewires the Data Center for 1 MW Racks
The power problem in AI is usually described at the scale of the grid: gigawatts of new load, years-long interconnection queues, gas turbines and nuclear deals. Nvidia's latest push is about the last few meters. At the Open Compute Project Global Summit this week, the company and about 20 industry partners showed equipment for 800-volt direct current data centers, a redesign of how power reaches the chips that Nvidia says is needed once a single rack draws a megawatt.
"Moving to 800VDC infrastructure from traditional 415 or 480 VAC three-phase systems offers increased scalability, improved energy efficiency, reduced materials usage, and higher capacity for performance in data centers," Nvidia said, as reported by Data Center Dynamics. Today's AI racks distribute power inside the rack at 54 volts DC. The company's current GB200 NVL72 and GB300 NVL72 racks already use up to eight power shelves. Nvidia's design converts 13.8 kV alternating current from the grid directly to 800 volts DC at the edge of the data center using industrial rectifiers, eliminating most intermediate conversion steps.
Row-level busways then carry 800 volts DC to the racks, which receive it directly, removing the AC to DC conversion inside each rack and freeing space for computing hardware. The architecture is built for Kyber, the successor to Nvidia's current Oberon rack design, which will house 576 Rubin Ultra GPUs by 2027. Nvidia also outlined the Vera Rubin NVL72 rack, which uses 45°C liquid cooling, a new liquid-cooled busbar and 20 times more energy storage to keep power steady.
The design also cuts the number of power supply units with fans in the power chain. Several chipmakers said the shift requires new power semiconductors, particularly silicon carbide and gallium nitride, to handle the higher voltages efficiently, according to DCD. What it does change is how quickly that power can be put to use. For utilities and grid planners, the takeaway is that the unit of AI demand is getting bigger.