[Beowulf] choosing a high-speed interconnect

[Chris Sideroff]

On Tue, 2004-10-12 at 16:48, Joe Landman wrote:
> First questions first:
> 
>   Why do you think you need a faster network, and what aspect of fast do 
> you think you need?  Low latency?  High bandwidth?

  To tell you the truth I can't answer that with more than, "I have a
gut feeling".  I am in the process of profiling the performance of our
current cluster with our programs.  Any suggestions ???

> Then...
> 
>   What codes are you running?  Across how many CPUS?  Have you done a 
> performance analysis on your system to observe "slow" runs in progress, 
> and are you convinced that the network is the issue?

   We run exclusively computation fluid dynamics on it.  One program is
Fluent the other is an in-house turbo-machinery code.  My experiences so
far have led me to believe Fluent is much more sensitive to the
network's performance than the in-house program.  Thus my inquiry into a
higher performance network.

> We have done lots of tuning bits for customers where the issues wound up 
> being something else than what they had thought.  It is worth at least 
> looking into for your code/problems, and identifying the bottleneck (if 
> you haven't already done so).

  Do you have more information on this 'tuning for customers'.  I am
interested in your results.  Again any suggestions on how to go about
this are welcomed.

Thanks, Chris