Thi is largely card dependent I suspect. Cisco specifies 100amps I believe for their dc power supplies on 12008s, a company I worked for previously ran 25 amp circuits with 20 amp breakers to each, and even the burst of a sudden power on doesn't get near enough to that to cause a problem. Brian On Tue, 16 Jan 2001, Jeff Cours wrote:
Sean Donelan wrote:
One thing that would help.
Sun, Dell, Cisco, Compaq, Juniper, etc. Can you please start listing the true power draw of your equipment, not just the fuse rating. It would make forcasting a lot easier, if we knew ahead of time how much the equipment will really draw.
I'm not sure they can. Doesn't the actual power draw of a piece of equipment depend on what it's doing? For example, a rack full of Pentium III's that are acting as routers are mostly doing integer calculations, running bus transceivers, and driving communications links. That same rack full of Pentium III's acting as a render farm for your favorite Hollywood movie will be doing floating point intensive calculations, wide-spread memory access, spinning the disk drives, and, because of the extra heat, working any variable-speed cooling fans harder. I'd expect a measurably higher current draw in the second case.
It might be possible to come up with some sort of average power draw, but Electrical Engineers really hate to give out numbers like that because people base their designs on them instead of on the worst case power draw, and then when something fries the EE winds up getting the blame. That's why most engineering disciplines derate components and allow a safety margin, which I suspect is where the fuse rating comes from.
- Jeff
-- Jeff Cours Senior Engineer UltraDNS, Inc