[Beowulf] Re: MS Cray

kyron at neuralbs.com kyron at neuralbs.com
Thu Sep 18 13:36:27 PDT 2008


>> Note that for the fully populated enclosure the power supplies are dual,
>> i.e.
>> 2* 1600W = 3200W.
>
> I see that now.  question for electrical-code enthusiasts on the list:
> isn't a normal "15 amp" office circuit actually supposed to only be
> used up to 12 amps?  that would mean 12*120=1440; in other words, each
> 1600W PS needs a special circuit.  also, isn't it pretty common for
> an office duplex receptacle to be fed by a single (15A) circuit?

Here is the _practical_ answer: YES. And here is why:

http://wiki.neuralbs.com/~kyron/WrongSpecs/dsc00884.jpg

> I guess what really surprises me is that Cray doesn't mention ScaleMP,
> which would seem to suit this box ideally.  if someone wants Windows,
> I'd very much expect them to want the convenience of ignoring the fact
> that memory is distributed...

Yes, that is what I was also asking in a spinoff thread and doubted that
it would have been the case.

IMHO, anyone is better off buying a Tyan-type SMP such as the VX50 we have
here. For about 25k$ CAD, we got 8x2core Opteron with 32Gigs of
ram...that's over a year ago and it's been running flawlessly since I
built it (except for dead ram due to power fluctuation/outage)

Eric




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