[realtek] 8139too performance - can you shed some light?

Carlo E. Prelz fluido@fluido.as
Thu, 2 Aug 2001 17:54:45 +0200

	Subject: Re: [realtek] 8139too performance - can you shed some light?
	Date: Wed, Aug 01, 2001 at 03:00:17PM -0700

Quoting Ben Greear (greearb@candelatech.com):

> See if you can tell where the pkts are being dropped, and for what
> reason.  Take a look at the /proc/net/dev file on all the machines,
> for instance.  You can also increase the kernel buffers for sockets.  If you do a
> netstat -an | grep udp, then you can see your current buffer usage,
> and that may give you some ideas.  Do that many times because the buffers
> fill and un-fill quickly.  Finally, you can try increasing
> the driver TX buffers.

I spent the whole day exploring the problem, and I reached the
conclusion that the bottleneck is in the processor. I tried the same
software with a PII-400MHz and it sustained exactly the data rate I
expected. I trtied to fit the SBC with 256MB of memory, but the
situation did not get better. Evidently the simple processing power
that is required to handle sustained 100MBps traffic is too much for a
Pentium-mmx class cpu running at 233MHz. When given enough processing
power, the system runs real smooth.

Many thanks for dedicating some time to my problem. 

Happy <fill the blank> 


  *         Se la Strada e la sua Virtu' non fossero state messe da parte,
* K * Carlo E. Prelz - fluido@fluido.as             che bisogno ci sarebbe
  *               di parlare tanto di amore e di rettitudine? (Chuang-Tzu)