> > I agree with Bill that performance portability is an issue. That is, the > MPI standard itself doesn't really provide any guarantees here about what is > fastest. Perhaps polling this mailing list will be helpful, but if you are > looking for "the fastest" solution regardless of which MPI implementation > you use (and which interconnect you use... which might be determined at run > time) you will probably be disappointed. >
I was afraid that was going to be the case :-( So if I'm concerned about being network-BW-bound and being performant on different types of architectures I should design my application such that it is able to use any of the above communication patterns such that I can tell the app which comm-pattern to use depending on the middleware/hardware it will run on (to optimise for BW usage) ? toon
