[Beowulf] Anyone have experience with Cisco 6509 switches for a cluster?

[Bogdan Costescu]

On Wed, Jun 15, 2011 at 16:27, Joe Landman
<landman at scalableinformatics.com> wrote:
>   This suggests that all traffic is being serialized somehow, possibly
> transiting a single interface.

I seem to remember on at least some Cisco cards ports being "bundled",
organized like a 2-level tree. Each bundle of 8 ports communicate at
wire speed between them, but share a common 1GB link to the upper tree
level. The card itself might have had some further limitation when
connecting to the backplane. Depending on the pattern of the
nodes/ports that were involved in the test, this might explain the
different results.

Cheers,
Bogdan