[Beowulf] typical latencies for gigabit ethernet

Rahul Nabar rpnabar at gmail.com
Mon Jun 29 14:24:48 PDT 2009

On Mon, Jun 29, 2009 at 3:15 PM, Mark Hahn<hahn at mcmaster.ca> wrote:

Thanks for all the help Mark!

> well, ping is not _really_ a benchmark ;)

I thought so! :) Lazy person's first shot. Now I will try ethtool.

> but it does sound like you have interrupt coalescing enabled.
 Any way to verify if I do?

>  ping is also reporting round-trip,

Ah! So my "real" latencies are 140/2 = 70 microsecs. That doesn't
sound so terribly bad now.

> well, look at "ethtool -c" output and try with "ping -s 20".

Tried this. No improvement. Still round-trip-pings are  in the 140
microsec range.


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