RE: [myrinet] collective comms w/ SMP nodes

> We are considering a cluster configuration with dual Pentium III nodes
> connected by Myrinet.  Has anyone looked at the performance of
> collective communication routines (all-to-all, etc.) using MPICH on
> Myrinet with/without  SMP support?  It seems that collective
> communications would be slow when multiple processors are sharing a PCI
> bus.

The mpich standard collective routines are completely naive, so I doubt
you'd notice the PCI bus as a bottleneck on a medium-to-large system,
compared to the inefficient algorithms.

-- g