  This paper evaluates the optimal scale of datacentre (DC) resource
disaggregation for composable DC infrastructures and investigates the impact of
present day silicon photonics technologies on the energy efficiency of
different composable DC infrastructures. We formulated a mixed integer linear
programming (MILP) model to this end. Our results show that present day silicon
photonics technologies enable better network energy efficiency for rack-scale
composable DCs compared to pod-scale composable DCs despite reported
similarities in CPU and memory resource power consumption.
