> Lower voltage would be OK, but then all of the cables and plugs would need to be redesigned. And there would still need to be for voltage switching unless we start adding a protocol and have PSU switch voltage dynamically... which is also not efficient.
It's not like that. It's a design where PSU only provides 12V to motherboard and motherboard provides the rest. Only location of those connectors change. It's called ATX12VO.
In modern PC almost nothing draws from 3v3 rail, not even RAM. I'm pretty sure nothing draws 3v3 directly from PSU at all today.
5v rail directly from PSU only used for SATA drives.
It's not like that. It's a design where PSU only provides 12V to motherboard and motherboard provides the rest. Only location of those connectors change. It's called ATX12VO.
In modern PC almost nothing draws from 3v3 rail, not even RAM. I'm pretty sure nothing draws 3v3 directly from PSU at all today.
5v rail directly from PSU only used for SATA drives.