Tackling the Power Challenge in AI Data Centers with HPE Networking

With power becoming a hard constraint on AI expansion, every watt consumed by the network reduces the power available for productive GPU compute. Learn how efficient design in silicon, optics, liquid cooling, and visibility & analytics minimize power consumption. At Networking Field Day 41, Yogesh Kumar, Senior Director of Product Management for Data Center Networking at HPE, framed network efficiency as a matter of compute capacity rather than sustainability. Facility power can take years to provision and is capped once delivered, so every watt the network saves can go back to GPUs.

Kumar described four levers. The first is staying on current silicon generations, since each one improves power per bit. The second is optics: moving from fully retimed modules to linear receive and linear pluggable optics, and eventually to near-packaged and co-packaged designs. The third is liquid cooling, which eliminates fans and improves power usage efficiency. The fourth is network visibility. He highlighted the emerging XPO form factor, which bundles the equivalent of eight OSFPs into a liquid-cooled package. HPE views CPO and NPO as close variants and has experimented with them since the Tomahawk 5 generation, but it has not announced a CPO product. Delegates pressed on serviceability, since CPO lacks field-replaceable parts. Kumar noted that CPO links appear more reliable and that lasers can stay pluggable, while acknowledging that scale-up may eventually require co-packaged approaches.

The cooling discussion centered on the QFX5250, a fanless 102.4 Tbps switch with 64 ports of 1.6T in an ORv3 form factor, which began shipping in May ahead of other OEMs. Kumar said reaching 95% liquid cooling was straightforward, but the last 5% required heat pipes and copper paths to cool components that air would normally cool incidentally. That extra work spares customers rear-door heat exchangers. He credited HPE’s experience with coolant selection, supplier testing, and leak detection, which helped the team avoid over-engineering. For example, the team replaced sensor wiring along every pipe with drip plates and sensors placed at the joints where leaks actually occur. Kumar closed with HPE Data Center Assurance’s network sustainability analytics, which reports power and carbon data, forecasts consumption, and recommends actions such as shutting down unneeded ports, with the stated benefits and risks of each action.