netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Chris Friesen <cfriesen@nortelnetworks.com>
To: netdev@oss.sgi.com
Subject: strange e1000 performance issues
Date: Fri, 09 Apr 2004 03:23:53 -0400	[thread overview]
Message-ID: <40764F89.8090306@nortelnetworks.com> (raw)

I've got a pair of dual G5s running 2.6.4.  For a second gigE link we 
added in some Intel 82540EM cards, using the mainline e1000 driver with 
NAPI enabled.  lspci reports the bus as 66MHz.  The cards were connected 
together with a crossover cable.

A basic UDP packet-blasting program in userspace using 64KB datagrams 
could only manage 47MB/s of data throughput, using 20% of a cpu.

For comparison, the same program managed 108.9 MB/s with 30% cpu when 
using the onboard gigE ports.

Also, I tried setting a larger mtu using "ip set link dev ethx mtu 
xxxxx".  No matter what value I chose (even setting it to its default 
value, which should have had zero effect) it resulted in the link not 
being able to transfer data.  Downing/upping the link didn't clear the 
issue, neither did unloading/reloading the driver module.  It took a 
reboot to actually get it working again.

Any ideas what's going on?

Thanks,

Chris

                 reply	other threads:[~2004-04-09  7:23 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=40764F89.8090306@nortelnetworks.com \
    --to=cfriesen@nortelnetworks.com \
    --cc=netdev@oss.sgi.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).