Abstract: A power supply unit where the main DC voltage output rail is incorporated within the enclosure of the power supply unit and some DC voltage output rails and DC-DC converters are located outside the enclosure of the power supply unit close to or directly at the input of the system board and input of associated system peripheral via integration into a cable harness assembly, to negate the voltage drop on the cable harness assembly, resulting in a lower power loss across the cable harness assembly, leading to an improvement in combined power supply unit and cable harness assembly efficiency.