Hi, > * MVAPICH uses a multicast group for some MPI collectives > * This can be turned off by setting env var DISABLE_HARDWARE_MCST
MVAPICH uses h/w multicast for MPI_Bcast. We plan to extend this to other collectives in future, Thanks, Amith > > * An IB multicast group has to use ports of the same speed > * This one was a surprise to me > > Ergo, when you mix 1X, 4X SDR, and 4X DDR hosts, it behaves > differently from a homogeneous network. > > -- greg > _______________________________________________ > openib-general mailing list > [email protected] > http://openib.org/mailman/listinfo/openib-general > > To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general > _______________________________________________ openib-general mailing list [email protected] http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
