Datacenter Interconnects: Copper vs. Optics, Nvidia's 78-Layer PCB, Co-Packaged Optics (CPO)

Vik Sekar and Austin Lyons tackle the biggest bottleneck in inference: moving data. They break down the three tiers of datacenter networking — scale up, scale out, scale across — and the core engineering trade-off at each layer: copper vs. optics. Topics include Nvidia's extreme measures to keep scale-up fabric electrical (a 78-layer mid-plane PCB), why Co-Packaged Optics is the "holy grail" everyone wants and no one can ship, and the serviceability problem standing in its way. Key Takeaways:...