newbie - small node update (and some more questions!) gigabit?

[Eric Linenberg]

Thanks for the informative, quick responses everyone!
I do have a few more questions though...

What are the benefits/drawbacks of a gigabit network as compared to a
double bonded 100baseT network or a simple 100baseT network?  What
exactly is a double bonded network, and how big are the benefits in a
system like mine with 4 dual processor nodes?

I have been in contact with the professor, and due to space limitations it
seems we will be using a Tyan/AthlonMP combo -- only 4 boxes, but 8
processors, and a master box that we already have that is a dual 800
Intel Xeon box.  This should work out fine -- right?

So, I would really like to know what people's opinions and thoughts
are about gigabit in a system like this.  I have briefly looked for
places that sell gigabit switches and it seems a 6 port gigabit switch
is about $1300 and a gigabit card is about $200 (both by 3com at cdw.com)

switch:
http://www.cdw.com/shop/products/default.asp?EDC=244137
card:
http://www.cdw.com/shop/products/default.asp?EDC=272634

so, what cards and switches have you guys used on your systems out
there?  Is the gigabit option's performance worth it's price
difference (remember we have $25000, but do not necessarily want to
spend it all)  And, what are the best cards to use (as in most Linux
support, best/most stable drivers, etc) for a system like this.

I will probably be running the latest red hat distro, so please take
that into consideration.

Thanks so much,
Eric Linenberg