Want to move to all 208V for server racks

Sat Dec 4 05:33:46 UTC 2010

----- Original Message -----
> From: "Jima" <nanog at 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