Co-Packaged Optics (CPO) has long promised to transform datacenter connectivity, but it has taken a long time for the technology to come to market, with tangible deployment-ready products only arriving in 2025. In the meantime, pluggable transceivers have kept pace with networking requirements and remain the default path thanks to their relative cost-effectiveness, familiarity in deployment, and standards-based interoperability. However the heavy networking demands that come with AI workloads mean that this time is different. The AI networking bandwidth roadmap is such that interconnect speed, range, density and reliability requirements, will soon outpace what transceivers can provide. CPO will provide some benefit and bring more options to scale-out networking, but it will be central to scale-up networking. CPO will be the main driver of bandwidth increases in scale-up networking for the latter part of this decade and beyond. Today’s copper-based scale-up solutions, such as NVLink, provide tremendous bandwi…