Subject: Re: Performance of Alteon/Tigon Gigabit Ethernet cards
To: Manuel Bouyer <>
From: Hal Murray <>
List: tech-net
Date: 01/30/2001 14:46:53
> A yes, you need to increase NMBCLUSTERS


I'm already running with 4K.  These machines have a lot of network 
cards so that may not be enough. 

The out-of-buffers messages only happen when I run the UDP blast 
test.  I assume the buffers are all piling up on some to-be-dispatched 
input queue because there aren't enough CPU cycles to keep up with 
the sending side. 

Do all the queues have limit checks?  If I make NMBCLUSTERS big enough 
will the messages (and associated troubles) go away?

If not, making NMBCLUSTERS even bigger just means more buffers get 
on some queue before the messages start happening.

I might try commenting out the didn't-get-a-buffer message in each 
driver in hopes that the system will spend fewer cycles printing 
messages and thus have more to spend on processing buffers.

> I have a netgear in a DS20, it works pretty well.

What sort of throughput can you get?  How hard have you hit it?