During GTC 2025, NVIDIA released the NVIDIA Spectrum-X (based on the Ethernet standard) and NVIDIA Quantum-X (based on the InfiniBand standard) silicon photonic network switches, enabling AI factories to connect millions of GPUs across regions while significantly reducing energy consumption and operating costs.
NVIDIA Silicon Photonics CPO
The partners listed under the slide include: Broway Technologies, Coherent, Corning, Fabrinet, Foxconn, and Lumentum, etc.
CPO (co-packaged optoelectronics) assembles the network switching chip and optical transceivers together in the same slot, forming a co-package of the chip and the module. CPO technology can make chips more integrated and have more stable performance, while reducing packaging costs and improving packaging efficiency. Key technologies include:
- A 1.6T silicon photonic chip arranged five years in advance based on the Silicon Photonic Micro-Ring Modulator (MRM) developed by TSMC;
- The silicon photonic engine of TSMC’s 3D stacked electro-optical integration EPIC;
- High-power, high-efficiency external laser;
- Pluggable fiber optic connector;
- 100+ patents have been deployed and licensed to partners for joint development.
The Quantum-X Photonics Infiniband switch is a 115.2Tb/s silicon photonics CPO switch, a 144×800G version that includes four switch chips. Compared with pluggable optical transceiver solutions, it reduces energy consumption by 3.5 times, improves network elasticity by 10 times, and improves deployment efficiency by 1.3 times. It uses liquid cooling internally.
The switching chip is a 28.8Tb/s Quantum-X800 ASIC, which uses TSMC’s 4nm process and has an on-line computing capability of 3.6TFLOPS FP8 precision.
Six optical components, each of which contains 3 1.6T silicon photonic engines, totaling 18, are placed around the switching chips. Each optical engine has 2 external laser input ports (one for backup switching), through fiber input, and 16 fiber outputs, for a total of 324 fiber channels. The optical components are detachable and can be replaced and repaired.
The 1.6T silicon photonic engine consists of 8×200G silicon photonic micro-ring modulators, which reduces power consumption by 3.5 times compared to optical transceiver solution.
There are 4×288=1152 single mode optical fibers outside the switch, 144 MPO ports and 18 external optical transceiver ELS. A single module integrates 8 lasers, for a total of 144 lasers.
According to reports, NVIDIA Quantum-X Photonics InfiniBand switches are expected to be available later this year, and NVIDIA Spectrum-X Photonics Ethernet switches will be launched in 2026.