According to my research, it sounds as though power efficiency concerns in recent years have driven some hardware manufacturers to create different power supplies and motherboards which are "12V-only". That is to say, power supplies have been created to supply 12-volt power exclusively, directly to the motherboard. Motherboards, in turn, have been built or modified specifically to receive 12-volt power only and convert it into usable power for the various 12-volt, 5-volt, and 3.3-volt hardware components within the single computer associated with that motherboard.
From a technical perspective, what are the costs and benefits of adopting such an approach for powering a computer?
What about from an economic perspective?
Is this type of hardware available to the mainstream?