Optical modules are not being replaced by copper; instead, copper and optical technologies are coexisting, with optics dominating long-distance interconnects and copper remaining essential for short-range, in-rack connections.

Current Role of Copper and Optical Modules

Copper cables continue to play a critical role inside AI server racks due to their low latency, zero power consumption, and high reliability, making them indispensable for short-range connections within a single rack, especially in high-density GPU nodes . Optical modules, on the other hand, are primarily used for long-distance interconnects between racks, where copper's signal attenuation and crosstalk become limiting factors .

Technical Drivers for Optical Adoption

The rise of AI workloads has dramatically increased data rates and rack densities. Modern GPUs, such as NVIDIA's latest architectures, require multi-terabit per second interconnects, which exceed the practical limits of copper over longer distances . Optical fibers provide higher bandwidth, longer reach, and lower signal loss, making them essential for connecting multiple racks and data center backbones . Innovations like hollow-core fiber further reduce latency and nonlinear distortion, enhancing optical performance in AI-centric environments .

Coexistence Strategy

Industry leaders, including Nvidia, emphasize a dual-era approach where copper and optical modules coexist. Copper will remain dominant inside racks at least until 2027, while optical modules gradually penetrate in-rack connections with future platforms like Nvidia's Feynman system expected around 2028 . This approach allows data centers to balance power efficiency, latency, and bandwidth requirements while scaling AI infrastructure.

Market and Supply Implications

The demand for optical fibers and modules is growing rapidly, driven by AI data centers. Investments by companies like Nvidia and Meta in optical fiber manufacturing indicate a long-term expansion of optical capacity, but copper supply chains remain critical for in-rack connectivity . The transition is not a replacement but a specialization based on distance and performance needs.

Conclusion

Copper will not replace optical modules, nor will optical modules fully replace copper in the near term. Instead, the future of data center interconnects is a hybrid model, where copper handles short-range, high-reliability connections, and optical modules manage high-bandwidth, long-distance links. This coexistence ensures optimal performance, energy efficiency, and scalability for AI-driven data centers .