Mark,
Would it be feasible to downclock your three nodes? All you physicists know
better than I, that the power draw and heat production are not linear in
GHz. A 1 GHz processor is less than half the cost per tick than a 2GHz, so
if power budget is more urgent for you than time to completion then that
might help; continue running all of your nodes, but slower. But I've never
done this myself. OTOH as a mathematician I don't have to :-) See
http://xkcd.com/435/ ("Purity")
Peter
On 7/2/08, Mark Kosmowski <[EMAIL PROTECTED]> wrote:
>
> I'm in the US. I'm almost, but not quite ready for production runs -
> still learning the software / computational theory. I'm the first
> person in the research group (physical chemistry) to try to learn
> plane wave methods of solid state calculation as opposed to isolated
> atom-centered approximations and periodic atom centered calculations.
>
> It is turning out that the package I have spent the most time learning
> is perhaps not the best one for what we are doing. For a variety of
> reasons, many of which more off-topic than tac nukes and energy
> efficient washing machines ;) , I'm doing my studies part-time while
> working full-time in industry.
>
> I think I have come to a compromise that can keep me in business.
> Until I have a better understanding of the software and am ready for
> production runs, I'll stick to a small system that can be run on one
> node and leave the other two powered down. I've also applied for an
> adjunt instructor position at a local college for some extra cash and
> good experience. When I'm ready for production runs I can either just
> bite the bullet and pay the electricity bill or seek computer time
> elsewhere.
>
> Thanks for the encouragement,
>
> Mark E. Kosmowski
>
> On 7/1/08, ariel sabiguero yawelak <[EMAIL PROTECTED]> wrote:
> > Well Mark, don't give up!
> > I am not sure which one is your application domain, but if you require
> 24x7
> > computation, then you should not be hosting that at home.
> > On the other hand, if you are not doing real computation and you just
> have a
> > testbed at home, maybe for debugging your parallel applications or
> something
> > similar, you might be interested in a virtualized solution. Several years
> > ago, I used to "debug" some neural networks at home, but training
> sessions
> > (up to two weeks of training) happened at the university.
> > I would suggest to do something like that.
> > You can always scale-down your problem in several phases and save the
> > complete data-set / problem for THE RUN.
> >
> > You are not being a heretic there, but suffering energy costs ;-)
> > In more places that you may believe, useful computing nodes are being
> > replaced just because of energy costs. Even in some application domains
> you
> > can even loose computational power if you move from 4 nodes into a single
> > quad-core (i.e. memory bandwidth problems). I know it is very nice to be
> > able to do everything at home.. but maybe before dropping your studies or
> > working overtime to pay the electricity bill, you might want to
> reconsider
> > the fact of collapsing your phisical deploy into a single virtualized
> > cluster. (or just dispatch several threads/processes in a single system).
> > If you collapse into a single system you have only 1 mainboard, one HDD,
> one
> > power source, one processor (physically speaking), .... and you can
> achieve
> > almost the performance of 4 systems in one, consuming the power of....
> well
> > maybe even less than a single one. I don't want to go into discussions
> about
> > performance gain/loose due to the variation of the hardware architecture.
> > Invest some bucks (if you haven't done that yet) in a good power source.
> > Efficiency of OEM unbranded power sources is realy pathetic. may be
> 45-50%
> > efficiency, while a good power source might be 75-80% efficient. Use the
> > energy for computing, not for heating your house.
> > What I mean is that you could consider just collapsing a complete "small"
> > cluster into single system. If your application is CPU-bound and not I/O
> > bound, VMware Server could be an option, as it is free software
> > (unfortunately not open, even tough some patches can be done on the
> > drivers). I think it is not possible to publish benchmarking data about
> > VMware, but I can tell you that in long timescales, the performance you
> get
> > in the host OS is similar than the one of the guest OS. There are a lot
> of
> > problems related to jitter, from crazy clocks to delays, but if your
> > application is not sensitive to that, then you are Ok.
> > Maybe this is not a solution, but you can provide more information
> regarding
> > your problem before quitting...
> >
> > my 2 cents....
> >
> > ariel
> >
> > Mark Kosmowski escribió:
> >
> > > At some point there a cost-benefit analysis needs to be performed. If
> > > my cluster at peak usage only uses 4 Gb RAM per CPU (I live in
> > > single-core land still and do not yet differentiate between CPU and
> > > core) and my nodes all have 16 Gb per CPU then I am wasting RAM
> > > resources and would be better off buying new machines and physically
> > > transferring the RAM to and from them or running more jobs each
> > > distributed across fewer CPUs. Or saving on my electricity bill and
> > > powering down some nodes.
> > >
> > > As heretical as this last sounds, I'm tempted to throw in the towel on
> > > my PhD studies because I can no longer afford the power to run my
> > > three node cluster at home. Energy costs may end up being the straw
> > > that breaks this camel's back.
> > >
> > > Mark E. Kosmowski
> > >
> > >
> > >
> > > > From: "Jon Aquilina" <[EMAIL PROTECTED]>
> > > >
> > > >
> > >
> > >
> > >
> > > > not sure if this applies to all kinds of senarios that clusters are
> used
> > in
> > > > but isnt the more ram you have the better?
> > > >
> > > > On 6/30/08, Vincent Diepeveen <[EMAIL PROTECTED]> wrote:
> > > >
> > > >
> > > > > Toon,
> > > > >
> > > > > Can you drop a line on how important RAM is for weather forecasting
> in
> > > > > latest type of calculations you're performing?
> > > > >
> > > > > Thanks,
> > > > > Vincent
> > > > >
> > > > >
> > > > > On Jun 30, 2008, at 8:20 PM, Toon Moene wrote:
> > > > >
> > > > > Jim Lux wrote:
> > > > >
> > > > >
> > > > > > Yep. And for good reason. Even a big DoD job is still tiny in
> > Nvidia's
> > > > > >
> > > > > >
> > > > > > > scale of operations. We face this all the time with NASA work.
> > > > > > > Semiconductor manufacturers have no real reason to produce
> > special purpose
> > > > > > > or customized versions of their products for space use, because
> > they can
> > > > > > > sell all they can make to the consumer market. More than once,
> > I've had a
> > > > > > > phone call along the lines of this:
> > > > > > > "Jim: I'm interested in your new ABC321 part."
> > > > > > > "Rep: Great. I'll just send the NDA over and we can talk about
> > it."
> > > > > > > "Jim: Great, you have my email and my fax # is..."
> > > > > > > "Rep: By the way, what sort of volume are you going to be
> using?"
> > > > > > > "Jim: Oh, 10-12.."
> > > > > > > "Rep: thousand per week, excellent..."
> > > > > > > "Jim: No, a dozen pieces, total, lifetime buy, or at best maybe
> > every
> > > > > > > year."
> > > > > > > "Rep: Oh...<dial tone>"
> > > > > > > {Well, to be fair, it's not that bad, they don't hang up on
> you..
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > Since about a year, it's been clear to me that weather
> forecasting
> > (i.e.,
> > > > > > running a more or less sophisticated atmospheric model to provide
> > weather
> > > > > > predictions) is going to be "mainstream" in the sense that every
> > business
> > > > > > that needs such forecasts for its operations can simply run them
> > in-house.
> > > > > >
> > > > > > Case in point: I bought a $1100 HP box (the obvious target group
> > being
> > > > > > teenage downloaders) which performs the HIRLAM limited area model
> > *on the
> > > > > > grid that we used until October 2006* in December last year.
> > > > > >
> > > > > > It's about twice as slow as our then-operational 50-CPU Sun Fire
> > 15K.
> > > > > >
> > > > > > I wonder what effect this will have on CPU developments ...
> > > > > >
> > > > > > --
> > > > > > Toon Moene - e-mail: [EMAIL PROTECTED] - phone: +31 346
> > 214290
> > > > > > Saturnushof 14, 3738 XG Maartensdijk, The Netherlands
> > > > > > At home: http://moene.indiv.nluug.nl/~toon/
> > > > > > Progress of GNU Fortran:
> > http://gcc.gnu.org/ml/gcc/2008-01/msg00009.html
> > > > > >
> > > > > >
> > > > > >
> > > > > _______________________________________________
> > > > > Beowulf mailing list, Beowulf@beowulf.org
> > > > > To change your subscription (digest mode or unsubscribe) visit
> > > > > http://www.beowulf.org/mailman/listinfo/beowulf
> > > > >
> > > > >
> > > > >
> > > >
> > > > --
> > > > Jonathan Aquilina
> > > >
> > > >
> > > _______________________________________________
> > > Beowulf mailing list, Beowulf@beowulf.org
> > > To change your subscription (digest mode or unsubscribe) visit
> > http://www.beowulf.org/mailman/listinfo/beowulf
> > >
> > >
> > >
> >
>
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