[Beowulf] Re: energy costs and poor grad students

Wed Jul 2 06:11:46 PDT 2008

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 <asabigue at fing.edu.uy> 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" <eagles051387 at gmail.com>
> > >
> > >
> >
> >
> >
> > > 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 <diep at xs4all.nl> 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: toon at moene.indiv.nluug.nl - 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
> > > > >
> > > > >
> > > > >
> > > > _______________________________________________
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> > > >
> > > >
> > >
> > > --
> > > Jonathan Aquilina
> > >
> > >
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