[Beowulf] Home beowulf - NIC latencies

[John Hearns]

On Fri, 2005-02-04 at 21:39 +0100, Vincent Diepeveen wrote:

> >
> >So that operation will cost around 80us with GigE, and 10-16us with IB
> >or Myri.
> 
> 80 us is what i read elsewhere too yes for GigE. 
> 
> Is it so hard to make a card with lower latency for a few dollar?
> 
> I mean if i buy for 135 euro a cpu i can get myself an opteron 1.4Ghz or
> something. If i buy for 1000 euro i get myself say a 2.4Ghz opteron.

We supply turnkey clusters with the SCore environment, which gives
excellent latency figures using standard gigabit ethernet NICs.


If you are looking for different hardware, Google for 'TOE' - TCP
Offload Engine. These are claimed to offer lower latency than onboard
adapters. But caveats apply: I've no idea how these work with MPI type
applications, as they're probably aimed at high bandwidth applications,
and it is probably more cost effective to go Myrinet/Quadrics/IB

Actually, it would be worth having the list's opinions on TOE adapters.
My guess is that they really don't do much for the latency, but
would be very good on webservers and databases servers.