As AI clusters grow larger, they begin to use optical interconnects for scale-out connectivity. However, the day when they require optical interconnects for scale-up connectivity may be approaching soon. To prep for that day, hyperscalers Microsoft, Meta, and OpenAI teamed up with hardware designers AMD, Broadcom, and Nvidia to develop a protocol-agnostic scale-up interconnection technology for AI clusters.
To do so, the group of companies this week established the Optical Compute Interconnect (OCI) Multi-Source Agreement (MSA) group to define an open optical connectivity specification for scale-up interconnections used inside large AI systems and racks to enable hyperscalers to use optical cables instead of copper to connect more accelerators at high speed and predictable power. In practice, this means the consortium will develop a common optical physical layer (PHY) and unified components to support various protocols, such as UALink for AMD and Broadcom, and NVLink for Nvidia.
