48v seems vastly safer. There's 1/4 the thermal heating for equivalent power. The new high density 12VHPWR connector for GPUs has been melting down & had to get basically redesigned. That would not have been a problem at all on 48V.
There shouldn't be an intermediary step down to 12V. Google's been doing direct step down from 48V->~1V with GaN fets for half a decade, which is vastly more power efficient than the two step 277V->12->1V that many server systems go through.
It'd also be amazing to have usb-c extended power (48v) be something we could just add for free, essentially. (Alas this is complicated by needing to step down to lower voltages too, necessities some semiconductors in the delivery path to usb-c, which would have some voltage drop. This strongly implies to me something more like 52V or 54V would be ideal instead of 48V.)
For anything that typically runs under 100W, I agree that 48V is ridiculous. But I would love love love to see some motherboards for ThreadRipper that have GaN fet for direct conversion from 48V, or stuff like that. It'd be pretty niche. But it should be an option!
One of the big potential winners could be people with solar; being able to run your system directly off your solar bank would save double digits percent of power, versus inverting then converting back.
You're right that in the immediate term we'd see a lot of intermediary conversions. I'd love to have a better game plan, for not just motherboards but other components to expect either 48v or wider voltage inputs. Non-trivial to support 10-60V but if that was a market expectation & not a niche need we'd see very affordable solutions spring up practically overnight. There's already a range of usb-c focused power converters that are exceedingly cheap that could step in for this need!
Edit: seems like Google is using two stage conversion primarily, but not necessarily 4:1 48V:12V. Their fixed ratio converter seems to have a 6:1 mode (8V) target as well, or be configurable for even bigger ratio (they said up to 12:1 in their talk). As of 2019, a bit of change of tune from original 2016 ambitions. Good talk? https://youtu.be/aBkz2JR4UVs
There shouldn't be an intermediary step down to 12V. Google's been doing direct step down from 48V->~1V with GaN fets for half a decade, which is vastly more power efficient than the two step 277V->12->1V that many server systems go through.
It'd also be amazing to have usb-c extended power (48v) be something we could just add for free, essentially. (Alas this is complicated by needing to step down to lower voltages too, necessities some semiconductors in the delivery path to usb-c, which would have some voltage drop. This strongly implies to me something more like 52V or 54V would be ideal instead of 48V.)
For anything that typically runs under 100W, I agree that 48V is ridiculous. But I would love love love to see some motherboards for ThreadRipper that have GaN fet for direct conversion from 48V, or stuff like that. It'd be pretty niche. But it should be an option!
One of the big potential winners could be people with solar; being able to run your system directly off your solar bank would save double digits percent of power, versus inverting then converting back.
You're right that in the immediate term we'd see a lot of intermediary conversions. I'd love to have a better game plan, for not just motherboards but other components to expect either 48v or wider voltage inputs. Non-trivial to support 10-60V but if that was a market expectation & not a niche need we'd see very affordable solutions spring up practically overnight. There's already a range of usb-c focused power converters that are exceedingly cheap that could step in for this need!
Edit: seems like Google is using two stage conversion primarily, but not necessarily 4:1 48V:12V. Their fixed ratio converter seems to have a 6:1 mode (8V) target as well, or be configurable for even bigger ratio (they said up to 12:1 in their talk). As of 2019, a bit of change of tune from original 2016 ambitions. Good talk? https://youtu.be/aBkz2JR4UVs