NVIDIA has developed co-packaged optics (CPO) technology with TSMC for its upcoming Quantum-X InfiniBand and Spectrum-X Ethernet switches, integrating silicon photonics directly onto switch ASICs. The engineering approach reduces power consumption by 3.5x. It decreases signal loss from 22 dB to 4 dB compared to traditional pluggable optics, addressing critical power and connectivity limitations in large-scale GPU deployments, especially in 10,000+ GPU systems. The architecture incorporates continuous wave laser sources within the switch chassis, consuming 2 W per port, compared to the 10 W required by conventional externally modulated lasers in pluggable modules. This configuration, combined with integrated optical engines that use 7 W versus 20 W for traditional digital signal processors, reduces total optical interconnect power from approximately 72 MW to 21.6 MW in a 400,000 GPU data center scenario.

Specifications for the Quantum 3450-LD InfiniBand model include 144 ports running at 800 Gb/s, delivering 115 Tb/s of aggregate bandwidth using four Quantum-X CPO sockets in a liquid-cooled chassis. The Spectrum-X lineup features the SN6810 with 128 ports at 800 Gb/s (102.4 Tb/s) and the higher-density SN6800 providing 512 ports at 800 Gb/s for 409.6 Tb/s total throughput. The Quantum-X InfiniBand implementation uses a monolithic switch ASIC with six CPO modules supporting 36 ports at 800 Gb/s, while the Spectrum-X Ethernet design employs a multi-chip approach with a central packet processing engine surrounded by eight SerDes chiplets. Both architectures utilize 224 Gb/s signaling per lane with four lanes per port. NVIDIA's Quantum-X switches are scheduled for availability in H2 2025, with Spectrum-X models following in H2 2026.Below is a video with more technical specs, in case you are interested, with nice showcase of what these switches are capable of.