[Fwd: Re: 32-port gigabit switch]

[Jeffrey B. Layton]

Dave Vehrs wrote:

>Rogerio,
>
>If you do the math, you will find that Myrinet quickly becomes less
>expensive than Gigabit as it scales to large node counts.  While Gigabit
>PCI cards are inexpensive, Gigabit switches are not.  In our experience,
>at ~64 nodes and above, Myrinet will be cheaper than Gigabit.
>

In my experience the sweet-spot is about 128-256 nodes.
Hopefully IB will change everything ;)


>
>Additionally the latency on Gigabit is simply to high for large
>clusters.  Remember on clusters latency is more important than
>throughput. 
>

Bzzt. Wrong. Dead Wrong. "It depends" is the correct answer. (Don't
pass GO, don't collect $200).

Jeff