On Tue, Feb 23, 2010 at 05:35:41PM -0500, Brian Dobbins wrote: > Well, clearly we hope to move more towards hybrid methods -all that's old > is new again?-
If you want bad performance, sure. If you want good performance, you want a device which supports talking to a lot of cores, and then multiple devices per node, before you go hybrid. The first two don't require changing your code. The last does. The main reason to use hybrid is if there isn't enough parallelism in your code/dataset to use the cores independently. > But getting back to a technical vein, is the multiplexing an issue due to > atomic locks on mapped memory pages? Or just because each copy reserves its > own independent buffers? What are the critical issues? It's all implementation-dependent. A card might have an on-board memory limit, or a limited number of "engines" which process messages. Even if it has a option to store some data in main memory, often that results in a scalability hit. -- greg _______________________________________________ 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
