The NVIDIA GB300 NVLink Liquid-Cooled Switch

At this year’s GTC conference, NVIDIA introduced its latest GB300 AI chip and AI server. However, detailed information on the GB300 liquid-cooled switch has been scarce. The following images of the GB300 NVLink liquid-cooled switch were provided by the overseas partner STH.

Displayed at NVIDIA GTC 2025, the GB300 NVLink switch tray is positioned between the GB300 compute blades. Unlike many contemporary switch designs, this unit employs a liquid-cooling system, rendering it compatible with the NVL72 rack.

The switch tray features a prominent handle at the front, followed by liquid cooling nozzles at the rear, a bus power supply, and connectors for four NVLink cable assemblies.

An especially ingenious aspect of the design lies in the fact that, although the NVLink switch chip is liquid-cooled, it is not the only component utilizing liquid cooling.

This image shows the cooling plate for the NVLink Switch section. In practice, the actual NVLink Switch PCB is considerably shorter in length compared to the depth of the chassis.

The power distribution can be clearly observed in this view.

While mainstream liquid-cooled servers typically employ rubber hoses, this design predominantly uses metal pipes. Although this may appear to be a minor detail, it serves as a distinctive design feature.

At the bottom of the assembly, several control components are visible, including an M.2 SSD.

Although NVIDIA customarily masks many of the logos on its GTC 2025 display models, two chips—the Marvell 88E1514 and the Lattice LCMXO3D-9400HC—remain identifiable.

Conclusion

This brief overview introduces the NVLink Switch trays, which will be integrated into the forthcoming GB300 NVL72 racks. More of these racks are expected to appear later this year, even though the majority of the market is currently still producing and utilizing the GB200 NVL72 racks. Nonetheless, NVIDIA’s commitment to liquid cooling is a hallmark of this generation, and as we move into the Rubin era, this commitment is poised to accelerate further.