NVIDIA deploys 1.6 Tbps Ethernet switches to support AI factories with millions of GPUs, with general availability coming later.

Nvidia is advancing its networking technology by integrating co-packaged optics (CPO) into its Quantum InfiniBand and Spectrum Ethernet switches, a move expected to reduce power consumption and cost in AI data centers. At its GTC 2025 event, Nvidia detailed plans for deploying silicon photonics directly into switch ASICs rather than relying on traditional pluggable transceivers. Nvidia's Spectrum-X and Quantum-X switches use this silicon photonics approach to deliver higher bandwidth and lower energy consumption, supporting up to 1.6 terabits per second (Tbps) per port to efficiently connect millions of GPUs. The Quantum-X and Spectrum-X photonics switches offer configurations ranging from 128 ports at 800Gbps to 512 ports at 800Gbps, delivering total throughputs of up to 400Tbps.

The improvements are substantial. Nvidia's new switches improve energy efficiency by a factor of 3.5, while also reducing signal degradation. In a typical AI data center with 400,000 GPUs, conventional networking setups require millions of optical transceivers, consuming significant power. Nvidia's approach reduces total network power from 72 megawatts to 21.6 megawatts, dramatically improving sustainability. These gains come from embedding photonics directly into switch ASICs, cutting energy use and minimizing signal loss.

Jensen Huang, founder and CEO of NVIDIA, stated: "AI factories are a new class of data centers with extreme scale, and networking infrastructure must be reinvented to keep pace. By integrating silicon photonics directly into switches, NVIDIA is shattering the old limitations of hyperscale and enterprise networks and opening the gate to million-GPU AI factories." The Spectrum-X Ethernet platform is designed to enhance multi-tenant hyperscale deployments, while the Quantum-X InfiniBand switches deliver superior signal integrity and resilience.

Nvidia's new switches are set for release in late 2025 and 2026. The first model, the Quantum 3450-LD InfiniBand switch, launching in late 2025, will provide 144 ports of 800 Gb/sec connectivity and a total bandwidth of 115 Tb/sec. In 2026, the Spectrum SN6810 Ethernet switch will debut with 128 ports at 800 Gb/sec and an aggregate bandwidth of 102.4 Tb/sec. A larger Spectrum SN6800 model will also arrive in 2026, featuring 512 ports of 800 Gb/sec and a total throughput of 409.6 Tb/sec. While systems like the GB200 NVL72 still use thousands of copper cables via NVLink 5, as Nvidia progresses to NVLink 6, copper's limitations will become more apparent, reinforcing the need for photonic solutions in large-scale AI tool deployments.