[Beowulf] recommendations for a good ethernet switch for connecting ~300 compute nodes

[Rahul Nabar]

What are good choices for a switch in a Beouwulf setup currently? The
last time we went in for a Dell PowerConnect and later realized that
this was pretty basic.

I only have gigabit on the compute nodes. So no Infiniband / Myrinet
etc. issues. The point is that I will have about 300 compute nodes.
Should I go for one large switch or several stacked ones? In the past
I had resorted to just interconnecting two or more 48 port switches
with multiple ethernet cables but this is quite crude I believe. Of
course, the smaller switches tend to be cheaper so in the past it was
making more sense to hook them up together even at the price of taking
a performance hit.

The main traffic sources are MPI and NFS. (NFS is quite inefficient so
this time around I might play with another FS but still something that
allows global cross mounts from ~300 compute nodes) There is a variety
of codes we run; some latency sensitive and others bandwidth
sensitive.

Finally, what are the switch parameters I ought to be comparing. If
300 eth ports are chattering at once do I look at the max rated
switching capacity or something similar?

-- 
Rahul