The Spectrum-X and QuantumX switches integrate optical components directly into switch ASICs, eliminating traditional pluggable transceivers and promising significant improvements in power efficiency, signal integrity, and scalability. The announcement by NVIDIA CEO Jensen Huang at GTC 2025 regarding the introduction of Silicon Photonics (SiPh) based Co-Packaged Optics (CPO) switches, the Spectrum-X and Quantum-X platforms (see Figure 1), has been now some time ago, so it is probably a good moment to make a retrospective of the. Silicon photonics has emerged as a compelling platform for the creation of photonic integrated circuits (PICs), enabling monolithic co-integration of electronic and photonic elements on a single semiconductor chip [1, 2, 3]. Replacing pluggable transceivers with silicon photonics on the same package as the ASIC, NVIDIA CPO innovations provide 5x better power. In the last decade, silicon photonic switches are increasingly believed to be potential candidates for replacing the electrical switches in the applications of telecommunication networks, data center and high-throughput computing, due to their low power consumption (Picojoules per bit), large.