Re: [Beowulf] Good demo applications for small, slow cluster

2013-08-21 Thread tegner
Maybe "paraview"? Scientifc visualization kit, working in parallel. "Ellis H. Wilson III" skrev: >Jim, > >Not sure if this "demo application" reaches beyond your intent, or if >it >really falls into the demo category, but Graph500 has a solid benchmark > >(by the same name) for graph-related prob

Re: [Beowulf] Good demo applications for small, slow cluster

2013-08-21 Thread Ellis H. Wilson III
Jim, Not sure if this "demo application" reaches beyond your intent, or if it really falls into the demo category, but Graph500 has a solid benchmark (by the same name) for graph-related problems, and there is an MPI version of it available in the source. You can scale the size of the problem

Re: [Beowulf] Good demo applications for small, slow cluster

2013-08-21 Thread Max R. Dechantsreiter
Hi Jim, What about something even simpler, nevertheless challenging: matrix multiplication? Slabs or blocks would be a major design choice. Superlinear scaling could be observed, showing a major performance advantage of parallelization on a cluster. Best regards, Max __

Re: [Beowulf] Good demo applications for small, slow cluster

2013-08-21 Thread Robert G. Brown
On Wed, 21 Aug 2013, Douglas Eadline wrote: > >> Sorts in general.. Good idea. >> >> Yes, we'll do a distributed computing bubble sort. >> >> Interesting, though.. There are probably simple algorithms which are >> efficient in a single processor environment, but become egregiously >> inefficient w

Re: [Beowulf] Good demo applications for small, slow cluster

2013-08-21 Thread Lux, Jim (337C)
Yeah, there was a POVray with parallelism that I've used. And a variety of "video wall" kind of things. What I was looking for was something that you could give as an assignment to a student "go code this in parallel, using this MPI-lite style library, and measure the performance". Rendering

Re: [Beowulf] Good demo applications for small, slow cluster

2013-08-21 Thread Max R. Dechantsreiter
Hi Peter, Not hardly: R. R. Coveyou (Knuth "Seminumerical Algorithms" 1981, 26-27): u[0] % 4 == 2 u[k+1] = u[k]*(u[k] + 1) % (1< Max, > Remarkable, thanks! I surely agree that in binary, doubling is fast. So you > sort of bypass computing low powers, with

Re: [Beowulf] Good demo applications for small, slow cluster

2013-08-21 Thread Peter St. John
Max, Remarkable, thanks! I surely agree that in binary, doubling is fast. So you sort of bypass computing low powers, with an ancient method (?!) of computing high powers efficiently. Very cool. So, everything is parallelizable :-) Peter On Wed, Aug 21, 2013 at 3:22 PM, Max R. Dechantsreiter < m.

Re: [Beowulf] Good demo applications for small, slow cluster

2013-08-21 Thread Max R. Dechantsreiter
Hi Peter, > That's interesting, where can I read about "giant-stepping the generator"? > The wiki article > http://en.wikipedia.org/wiki/Linear_congruential_generator doesn't > mention distributed processing. The term "giant-stepping" may not be in general use The idea is to find an efficient

Re: [Beowulf] Good demo applications for small, slow cluster

2013-08-21 Thread Peter St. John
Max, That's interesting, where can I read about "giant-stepping the generator"? The wiki article http://en.wikipedia.org/wiki/Linear_congruential_generator doesn't mention distributed processing. Thanks, Peter On Wed, Aug 21, 2013 at 2:44 PM, Max R. Dechantsreiter < m...@performancejones.com> wro

Re: [Beowulf] Good demo applications for small, slow cluster

2013-08-21 Thread Max R. Dechantsreiter
Hi Peter, > What about the old random number generator: take a 16 bit seed, square it, > take the middle 16 bits, and repeat. They'd want a large number in order > (so you can repeat an experiment, or a run of a model, with the same > "random" numbers), and it's easy to computer sequentially; but

Re: [Beowulf] Good demo applications for small, slow cluster

2013-08-21 Thread Max R. Dechantsreiter
Hi Jim, > Interesting, though.. There are probably simple algorithms which are > efficient in a single processor environment, but become egregiously > inefficient when distributed. Try anything requiring memory synchronization (such as atomic memory updates). Cheers, Max ___

Re: [Beowulf] Good demo applications for small, slow cluster

2013-08-21 Thread Max R. Dechantsreiter
Hi Douglas, Yes, "IS" - also "GUPS" is closely related (and easier to code, aside from its formal "lookahead" constraints). But I recommend crafting one's own, in order to have control over the key distribution: teach a lesson in load-balancing! Regards, Max --- On Wed, 21 Aug 2013, Douglas

Re: [Beowulf] The Mind Behind the Nascom-1

2013-08-21 Thread Lawrence Stewart
On Aug 21, 2013, at 12:57 PM, John Hearns wrote: > > > (*) ps.whatever happened to my 'first love' - emitter coupled logic? > I spent many happy hours as a graduate student (**) in learning about FASTBUS > for (at the time) > blazingly fast DAQ - because ECL goes faster. > I guess no-one can

[Beowulf] The Mind Behind the Nascom-1

2013-08-21 Thread John Hearns
http://www.theregister.co.uk/2013/08/21/unsung_heroes_dr_chris_shelton/ worth sticking with thsi article till page 4 - or indeed just advance straight to page 4. The concepts behind that PgC7000 processor were pretty revolutionary! An Ultra-RISC core, overclocking itself as much as it could, deco

Re: [Beowulf] Good demo applications for small, slow cluster

2013-08-21 Thread Peter St. John
Regarding "...There are probably simple algorithms which are efficient in a single processor environment, but become egregiously inefficient when distributed..." What about the old random number generator: take a 16 bit seed, square it, take the middle 16 bits, and repeat. They'd want a large numbe

Re: [Beowulf] Good demo applications for small, slow cluster

2013-08-21 Thread Douglas Eadline
> Sorts in general.. Good idea. > > Yes, we'll do a distributed computing bubble sort. > > Interesting, though.. There are probably simple algorithms which are > efficient in a single processor environment, but become egregiously > inefficient when distributed. e.g. The NAS parallel suite has an

Re: [Beowulf] Good demo applications for small, slow cluster

2013-08-21 Thread Lux, Jim (337C)
Sorts in general.. Good idea. Yes, we'll do a distributed computing bubble sort. Interesting, though.. There are probably simple algorithms which are efficient in a single processor environment, but become egregiously inefficient when distributed. Jim On 8/20/13 12:11 PM, "Max R. Dechantsreit