But you would then need to bring it down to the low voltages required by the chips and that would greatly increased cost, volume, weight, electrical noise and heat of the device.
Nah, modern GPUs are already absolutely packed with buck converters, to convert 12v down to 2v or so.
Look at the PCB of a 4090 GPU; you can find plenty of images of people removing the heatsink to fit water blocks. They literally have 24 separate transistors and inductors, all with thermal pads so they can be cooled by the heatsink.
The industry could change to 48v if they wanted to - although with ATX3.0 and the 16-pin 12VHPWR cable being so recent, I'd be surprised if they wanted to.
They could make a new spec for graphics cards and have a 24v/48v rail for them on a new unique connector.
I guess the problem is not only designing the cards to run on the higher voltages but also getting AMD and Intel on board because otherwise no manufacturer is going to make the new power supplies.
IIRC the patchwork of laws, standards and regulations across the world for low voltage wiring is what restricted voltage in the 36 V – 52 V range. Some locations treating it as low, some as an intermediate and others treated it as high voltage.
It may be marine market specific, but several manufacturers limit to 36v for even high amperage motors because of it.
Obviously I=V/R will force this in the future though.
The voltage step-down is already in place, from 12V to whatever 1V or 0.8V is needed. Doing the same thing starting from 48V instead of 12V does not change anything fundamentally, I guess.
It changes a lot. You are switching at different frequencies and although the currents are smaller, there is an increased cost if you want to do it efficiently and not have too many losses.
But anyway for consumer products this is unlikely to happen because it would force users to get new power supplies which would reduce their sales quite drastically at least for the first one they make like that.
The solution would maybe be to make a low volume 48V card and slowly move people over it showing them it is better?
Anyway this is clearly not a case of "just use X" where X is 48V. It is much more subtle than that.
Yes.
I'm not suggesting they increase the voltage, as i said, there are lots of tradeoffs.
But i'll also say - outside of heat, all of the things you listed are not safety concerns (obviously, electrical noise can be if it's truly bad enough, but let's put that one mostly aside).
Having a small, cost efficient, low weight device that has no electrical noise is still not safe if it starts fires.
