To reduce power consumption, easing cooling requirements, large computer designers are migrating from 12V to core voltage power solution to 48V to core voltage solutions. Some, but not all 48V to core voltage solutions being introduced do yield increased efficiency, but there are many other considerations and tradeoffs to wrestle with.
The well-proven buck regulator topology is highly strained in this application, while new topologies may be perceived as a reliability risk. New eGaN semiconductors, digital and analog non-linear control loops, and multi-phase controllers keep the buck topology on life support.
The paradigm shift to 48V direct to core voltage requires rethinking the power converter architecture and components from the top down.