Is this a correct summary of this thread? * IPoIB uses an InfiniBand multicast group to fake ethernet broadcast * This is optional, I'm not sure what functionality is lost without it
* MVAPICH uses a multicast group for some MPI collectives * This can be turned off by setting env var DISABLE_HARDWARE_MCST * 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
