----- Original Message -----
From: "Jima" <nanog@jima.tk>
On 12/3/2010 9:25 PM, Matthew Petach wrote:
(OK, so it's not as practical when you have other customers to worry about... but it might not be so crazy when you're looking at the efficiency numbers for 100,000 small 1u power supplies vs a set of much larger ones.)
Particularly if you're running your AC power through UPSes -- especially online ones (where there's a constant AC-DC-AC conversion happening). Go to DC for the batteries, never come back. It's a tempting notion.
And in fact, much carrier class equipment can be had with -48V power, there are ATX and similar power supplies for PCs that are -48, and I *think* I've commercial small UPSs (<3kVa) that give with -48 as well... using 48V battery strings, obviously. Cheers, -- jra