[Beowulf] hpl size problems

[Mark Hahn]

> workstations, because of both security and performance.  Things like
> ipchains or ipfilters tend to be "expensive" overhead on all TCP/UDP
> connections, and overhead in parallel computations is anathema.  So one

has anyone actually measured this?  I suspect that the marginal overhead
for iptables is ~1 us, and at least with gigabit, that's almost in the 
noise (say 3%).  I don't think anyone who is satisfied with gigabit 
would care...