Co-packaged optics goes commercial as AI networks hit a power wall

Summary

Copper interconnect is hitting reach and power limits as AI clusters scale, and co-packaged optics (CPO) is moving from demo to commercial deployment in 2026. Nvidia is bringing Quantum-X InfiniBand Photonics switches to market early in 2026 and Spectrum-X Ethernet Photonics in the second half, integrating optical engines directly onto the switch ASIC for up to 3.5x better power efficiency and 10x resiliency, the precondition for wiring million-GPU Rubin-era clusters. The strategy splits the field: Nvidia embeds photonics deep in a system-integrated architecture, while Broadcom pursues a modular, Ethernet-leveraged path; photonics startup Lightmatter is the wildcard, also inside NVLink Fusion. Optical interconnect borrows the same silicon-photonics base as photonic quantum.

By the numbers

• ~3.5x, power-efficiency gain from co-packaged vs pluggable optics.
• ~10x, network-resiliency improvement (fewer optical components).
• 400 Tb/s, top Spectrum-X Photonics switch throughput (512x 800Gb/s).
• H2 2026, Spectrum-X Ethernet Photonics commercial availability.
• 5 years, analyst estimate for all AI data-centre interconnects going optical.

Why it matters

At million-GPU scale, the optics, not the GPUs, set the power and reliability ceiling. Pluggable transceivers burn too much energy and fail too often; co-packaging light onto the switch is how AI networks keep scaling. It is also a new margin battleground: Nvidia, Broadcom and a wave of photonics startups are fighting for a layer that barely existed two years ago.

What to watch

• Spectrum-X Ethernet Photonics shipping on schedule in H2 2026.
• Nvidia's system-integrated vs Broadcom's modular CPO winning hyperscaler designs.
• Optical-engine yield and field reliability as the real scaling test.