Liquid Cooling Requirements for NVIDIA Blackwell GPUs
Why every GB200 and GB300 deployment requires 100% direct liquid cooling, and what facility operators need to prepare.
There is no air-cooled option for NVIDIA GB200 or GB300 NVL72 systems. Each rack draws approximately 120 kW, far exceeding what even the most aggressive air cooling systems can handle. Direct liquid cooling is mandatory.
The cooling architecture uses Coolant Distribution Units (CDUs) that interface between the facility chilled water loop and the rack-level cooling manifolds. Each CDU serves a specific number of racks, depending on the facility design and cooling capacity.
At the rack level, quick-disconnect fittings connect the cooling manifolds to individual GPU trays. These fittings must be rated for the operating pressure and temperature of the cooling loop. Improper installation can lead to slow leaks that damage equipment over time.
Leak detection is non-negotiable. Sensors are deployed at every connection point and along all coolant lines within the rack. The monitoring system must provide real-time alerts and, ideally, automated shut-off capability for affected cooling zones.
Facility operators planning for Blackwell deployments should verify their chilled water capacity, CDU placement locations, floor loading for fully-loaded liquid-cooled racks (approximately 1,360 kg per rack), and the routing paths for supply and return lines.