..snip.. > Potentially, of course, once you bite the bullet to parallelize, and you > do it in a scalable manner, then, you can presumably scale to > architectures where you have N cores running at full speed (e.g. A classic > cluster). I wonder, though, whether the end-user applications codes > actually do that, or whether they design for the "single user on a single > box" model. That is, they design to use multiple cores in the same > box,but don't really design for multiple boxes, in terms of concurrency, > latency between nodes, etc.
This in my mind is not an easy question to answer. Assuming an application can use more cores in a scalable fashion, the issue with SMP multi-core is how many effective cores you get vs actual -- due to memory contention. In my tests "it all depends on the application" One of the nice things about MPI codes is the ability to run on 16 separate nodes, one 16-way node, or anything in between. OpenMP has no way to get off the motherboard, but soon will open the door the onboard SIMD units. OpenMP does not guarantee an automatic win over MPI on multi-core either. -- Doug > > > James Lux, P.E. > Task Manager, FINDER Finding Individuals for Disaster and Emergency > Response > Co-Principal Investigator, SCaN Testbed (née CoNNeCT) Project > Jet Propulsion Laboratory > 4800 Oak Grove Drive, MS 161-213 > Pasadena CA 91109 > +(818)354-2075 > > > -- > Mailscanner: Clean > > _______________________________________________ > Beowulf mailing list, [email protected] sponsored by Penguin Computing > To change your subscription (digest mode or unsubscribe) visit > http://www.beowulf.org/mailman/listinfo/beowulf > -- Doug -- Mailscanner: Clean _______________________________________________ Beowulf mailing list, [email protected] sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
