On Oct 4, 2010, at 9:44 PM, Mark Hahn wrote: >> IN CLUSTER COMPUTING, IS THE AMOUNT OF CORE THAT COUNTS? > > no. it's the application 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? > > of course not. communication among cores on a single board > will certainly be faster than inter-board communication. > it's the application that matters: how frequently do threads/ranks > of the application communicate? are messages small or large? > can the app's communication be formulated as mostly-read sharing of data? > these are all very much properties of the application, > and they determine how suitable any particular hardware will be. > >> 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 > > power supplies aren't your main concern, since good ones are about 93% > efficient. but going with more-core systems is, in general, a good idea. > mainly for amortization reasons: probably fewer disks, extraneous sutff > like video interfaces, fewer parts to fail, fewer systems to administer, etc. > there can be disadvantages to more-core systems too, since some of the parts > being shared (amortized) may be performance bottlenecks. > > the sweet spots depends on what systems are in volume production - > right now, 2-socket systems are the right building block in most cases. > 4-socket systems would be attractive, but they tend to ship in so much > lower volume that their price is nonlinearly high. 1-socket servers > tend to cost more than half a 2-socket (where "server" means at least > "has ECC memory" - that is, not a desktop.)
the price point of the 4-socket Magny Cours systems are pretty attractive. Now that AMD did away with having to pay a premium for CPUs that were compatible with quad socket systems I think you can get more cores for the same amount of money by going quad socket Magny Cours. I purchased a small cluster mid summer, and went with 4-socket 32 core nodes. _______________________________________________ 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
