A rack unit configuration is described that includes a first printed circuit board (PCB) assembly interleaved with a second PCB assembly that is inverted with respect to the first PCB assembly. The configuration of the first PCB assembly and the second PCB assembly allow for increased component and power densities within computing systems, memory systems, etc. The increased density may be achieved while allowing sufficient mechanical clearance to allow easy component replacement and servicing (e.g., and hot pluggability). Power density may also be increased with PCB assemblies including nested and interleaved power modules.