HOWTO discriminate switches?

[Chris Wilson]

The situation is that we are trying to decide on the right switch for 
use in a 80 node cluster. The first option is to use a single switch with 
160+ fast ethernet ports. The second is to use eight 10 port gigabit 
switches plus the current gigabit switch for routing.

The codes to be run on the cluster are a mixture of the embarassing
parallel, bandwidth hog and latency sensitive -- which complicates
matters. :)

What I need is guidance on how to measure (and indeed what to be
measuring!) the switches to discriminate between the options. Presumably
netperf is a good starting point, but pointers to resources on switch
comparisions would be useful.

TIA.
-- 
 Chris Wilson                 {^_^}                 spam to bit.bucket at dev.null 
Anything that, in happening, causes itself to happen again, happens again.
                                                                    --  THHGTTG