Co-Packaged Optics (CPO) vs. Advanced Copper: The High-Speed Backplane Battle
Silicon photonics is moving directly onto the processor substrate. Discover how Co-Packaged Optics (CPO) threatens to displace traditional copper connectors in data centers.
The network infrastructure domain faces a fundamental architectural crossroads: continue squeezing performance out of advanced copper interconnects or transition fully to Co-Packaged Optics (CPO). In classic server designs, digital signals travel from the switch or processor ASIC across a PCB, pass through a copper backplane connector, and connect to optical transceivers at the faceplate. This journey introduces multiple points of impedance mismatch and considerable dielectric loss.
CPO solves this problem by moving the optical engines directly onto the processor substrate, right next to the silicon die. The electrical-to-optical conversion happens instantly over short trace distances.
By running fiber optic cables directly from the chip assembly to the backplane, the system eliminates the bulk of the copper path. While advanced copper connector manufacturers continue to innovate with tighter pitches and lower-loss contacts, the sheer thermal and power efficiency of routing photons instead of electrons over long backplanes is making silicon photonics a necessity for high-density AI clusters.