This paper presents efficient ways to implement one-to-all scatter communication
on k-ary n-cubes with multidestination message-passing. Earlier researchers have
applied multidestination message-passing to support non-personalized communications.
In this paper, for the first time in the literature, we demonstrate that multidestination
message-passing can also be used to support efficient personalized communication.
Current parallel systems use either a sequential tree-based (ST) scheme or a binomial
tree-based (BT) scheme with unicast message-passing to implement scatter. First, we
show that the ST scheme achieves the lower bound just for a narrow range of message
lengths. Next, we show that the BT scheme has a better overall performance compared to
ST but, it can never achieve the lower bound. Finally, we propose a sequential multidestination
tree-based (SMT) scheme using multidestination messages which minimizes the
scatter latency as well as achieves the lower bound. This scheme allows data for multiple
destinations to be grouped together and sent as a single message using multidestination
multicast/broadcast worms. All three schemes are evaluated for a range of system sizes
(k; n), communication start-up times (ts), propagation times (tp), and message lengths
(l). For small message sizes on an 8x8 torus, it is shown that the SMT scheme can
reduce the scatter latency up to a factor of 8 compared to the ST scheme and up to a
factor of 1.6 compared to the BT scheme. For a range of system sizes and (ts=tp) ratios,
it is shown that the SMT scheme performs better than the ST and BT schemes for a
wide range of message lengths. Thus, these results demonstrate significant potential to
be applied to design scalable collective communication libraries for current and future
generation wormhole systems.