On Oct 8, 2010, at 2:21 PM, Jeff Squyres wrote: > No. Open MPI does not have MPD -- I think you're thinking of a different MPI > implementation. :-)
Someone pointed out to me off-list that I wasn't quite clear here... *If* all of your architectures are the same endian and otherwise equivalent, you can just compile 32 bit and be ok. If your architectures are a mix of endians and/or other representations, you need the heterogeneous support. Also note that there is a --hetero flag to mpirun that you will need to use. Here's the relevant bit from mpirun(1): --hetero Indicates that multiple app_contexts are being provided that are a mix of 32/64-bit binaries. It seems a little klunky to have to specify --enable-heterogeneous in configure *and* specify --hetero on the command line, but as I mentioned, this is unfortunately not a common scenario and we therefore haven't really optimized it. :-\ I *swear* I just read in some of our documentation somewhere the part about mixing 32 and 64 bit MPI_DOUBLE (for example), but for the life of me, I can't find it now. :-( -- Jeff Squyres jsquy...@cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/