> IN CLUSTER COMPUTING, IS THE AMOUNT OF CORE THAT COUNTS? > If I build a cluster with 8 motherboards with 1 single core each would it > be the same as using just one motherboard but with two quad core > processors? I wanna build one of these but wanna save money and space and > if what counts is the amount of cores to process info I think fewer > motherboards with dual six-core processors is definitely cheaper just > because I wont be needing that many mothers power supplies etc. thanks
First the short and easy answer: "It all depends" Now the longer answer. A single 8-way system has plenty of advantages and four 2-way or eight 1-way systems certainly have a more overhead, cables, space etc. If you want to play with parallel computing and MPI the 8-way system will work just fine. (And yes, MPI works just fine on SMP systems.) OpenMP is also an option in this case, but remember, OpenMP will not "scale beyond the motherboard" (or at least there are no guarantees) while MPI can. I recently did a whole bunch of tests using both MPI and OpenMP a 12-way (dual 6-core) SMP box I will be posting soon. As I see it, one of the issues with the higher core counts is memory contention. An 8-way parallel program that hits hard on the memory may not scale as well as eight 1-way cores. This is where "it all depends" comes into play because it is very application dependent. I have a small script that I run on multi-core systems that uses the NAS parallel suite (single process) to give a hint at memory performance. I call it "effective cores." Check these two articles for some recent results: http://www.linux-mag.com/id/7855 http://www.linux-mag.com/id/7860 (you have to register, rather painless) <Shameless Plug> Note, the Limulus Project is an attempt to lower the overhead for small personal clusters. I'll have some news "real soon" about an 18-core design (one 6-way and three 4-way) that fits in one case and uses one power supply. More here: http://limulus.basement-supercomputing.com/ (there are links to pics and video) </Shameless Plug> -- Doug > > > > _______________________________________________ > 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 > > -- > This message has been scanned for viruses and > dangerous content by MailScanner, and is > believed to be clean. > -- Doug -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. _______________________________________________ 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
