Nvidia's 1.6Tbps switches to underpin meteoric rise of AI factories with millions of GPUs but you'll have to wait

Nvidia Quantum-X and Spectrum-X Silicon Photonics

(Image credit: Nvidia)

Nvidia’s Quantum-X and Spectrum-X switches reduce reliance on traditional optical transceivers
Silicon photonics boosts Nvidia’s network efficiency by 3.5x
Quantum-X and Spectrum-X switches deliver up to 400Tbps throughput for hyperscale AI factories

Nvidia is advancing its networking technology by integrating co-packaged optics (CPO) into its Quantum InfiniBand and Spectrum Ethernet switch, a move expected to reduce power consumption and cost in AI data centers.

At its GTC 2025 event, Nvidia detailed its plans for deploying silicon photonics, which will enhance efficiency by reducing the need for traditional optical transceivers.

Instead of relying on traditional pluggable transceivers, Nvidia is embedding photonics directly into switch ASICs, cutting energy use and minimizing signal loss. These advancements benefit hyperscale AI, and could also improve small business routers with similar efficiency gains.

Nvidia seeks to cut AI data center power by over 50%.

Nvidia’s Spectrum-X and Quantum-X switches use silicon photonics 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.

While the Spectrum-X Ethernet platform enhances multi-tenant hyperscale deployments, the Quantum-X InfiniBand switches deliver superior signal integrity and resilience, making them contenders for the best network switch.

“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,” said Jensen Huang, founder and CEO of NVIDIA.

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 could also enhance business smartphones, enabling faster, more reliable connectivity.

While Nvidia is transitioning towards optical networking, copper remains relevant in specific configurations.

Systems like the GB200 NVL72 still use thousands of copper cables to link GPUs and CPUs via NVLink 5, offering lower power consumption at the rack level.

However, 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.

Nvidia’s new switches are set for release in late 202 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.

Via Nextplatform