Open Compute systems are redefining how power is converted and distributed within an IT rack by replacing internal server power supplies with centralized, rack level, power supplies. This topic will cover an efficiency analysis of 3 rack architectures: Conventional internal server power supplies, 12VDC centralized rack level power supplies, and 48VDC centralized rack level power supplies. 48VDC rack distribution can provide the most efficient power path, the majority of gains come from reduction of PSU oversizing and centralizing to the rack level.