3 ms·
Not really. Pretty much the only PC part which wants native 12V would be the fans. All the other parts drop it down to 5V / 3V3 for auxiliary components, or 1-
by crote 3y ago
Not really.
Pretty much the only PC part which wants native 12V would be the fans. All the other parts drop it down to 5V / 3V3 for auxiliary components, or 1-2V for the CPU and GPU cores - which use the vast majority of power.
Dropping 12V DC to 1.5V is reasonably doable, but dropping 48V DC to 1.5V is a bit of a pain. In general you do not want to go beyond a 1:10 ratio for efficiency reasons, so 48V doesn't really gain you anything, while at the same time resulting in a massive compatibility break.
The push to 12VO is driven by a desire to get rid of technical debt. The 3V3 / 5V wires can't handle the current you need on those rails, so those are converted from 12V anyways. And literally nobody is using the -12V and -5V wires, so keeping those around is pointless.
- mkj 3y agoWhy does the ratio affect efficiency? Naively it seems like it should just be able to use differently sized inductors.
- namibj 3y agoOpen compute platform switched to 48V years ago, to afford having multiple PSUs feeding multiple servers, with (those days) a fixed 4:1 switched capacitor down converter right next to the existing 12V-to-0.5~1.5V DrMOS VRM power stages. There are iirc GaN devices from epc-co these days that make it feasible to go directly from 48V with the VRMs to the 0.5~1.5V for the core.