I agree with Ellis 100%. Ellis, if you're still a student, you've got a bright future ahead of you.
Prentice On 09/12/2012 12:02 PM, Ellis H. Wilson III wrote: > On 09/12/2012 11:42 AM, Vincent Diepeveen wrote: >> On Sep 12, 2012, at 5:24 PM, Lux, Jim (337C) wrote: >>> So, the question is... what's the smallest number of nodes in a >>> "demo/toy" cluster that gives you the "big iron" feeling. I'm >>> going to guess that 4 is too few. > I'd say even 16 would get you where you wanted to go, provided you get a > few smaller switches so the students can understand/run into network > topology problems (like why full bisection bandwidth really matters) as > well. If it's all on one switch networking will not really matter, > which it does a lot in "big iron." > >> But most important: working with junk slow old hardware is not >> interesting to students. They want to be FASTER than their home PC. >> So give them a cluster where the software running on it is FASTER >> than their home PC. >> >> That's your first priority, or they wll be all total desinterested. > As someone who is still a student and who first put together his first > Beowulf cluster in 2008 made from "totally crap" PIII's that were in > some science building's attic of my University, and can speak from > experience that this vantage point is totally wrong. I was perfectly > excited overcoming the issues to get the 4 PIIIs I had to go 4x faster > than 1 PIII, since after all, you are going to run into very similar > infrastructure problems with a newer machine anyhow. I was just > learning the ropes about scalability then, learning how to code in MPI, > how to properly profile and monitor my system, how to install things in > parallel, etc -- I wasn't trying to set a flop record or anything. This > would be like taking a collegiate mechanical engineering class and > expecting kids to make a go-kart that was all-around better than their > car sitting back in their parking lot -- totally unrealistic. > > In short, you've shared this negative, "if it's not faster then forget > about it" sentiment before Vincent, and it's neither constructive to the > conversation nor to be reasonably expected from Professors trying to run > a solid class on a budget. If I was the teacher, had a constrained > budget, and had the choice between 2 standard machines to share with the > whole class that WOULD go faster than the student's machines at home or > 16 Raspberry Pi's that WOULDN'T go faster (for most workloads) than the > home computer, I would of course choose the latter. > > When you are trying to educate people about cluster computing, the most > important thing is conveying the difficulties (both performance and > infrastructure related) working at scale -- not simply showing off that > the thing is "faster." Remember, students are paying CUSTOMERS for the > education; you should assume they are already interested in the concepts > and theory. It's not the educators job to spark this interest or feed > some flop-lust, but it is their job to expose as much of the theory and > pragmatics to the student as possible. This IS possible with MANY > slower machines, but ISN'T possible with FEW faster machines. If a few > students are being stubborn like you and want to drop the class because > the cluster isn't "fast enough," their loss. > > Best, > > ellis > _______________________________________________ > Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing > To change your subscription (digest mode or unsubscribe) visit > http://www.beowulf.org/mailman/listinfo/beowulf _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
