>
> I'll second this.
> It sounds a lot like the Gbps NICS are spending all day re-transmitting lost
> packets through under-spec'd cables.
>

To my experience "under-spec'd cables" is a more a myth than reality.
Usually it's crappy NIC's / crappy switches / crappy drivers. Of course
not a firebird problem at all.

Have you tried using something like iperf[1] to measure the network
performance under load?

[1] http://www.noc.ucf.edu/Tools/Iperf/default.htm

Michael