From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Fink Subject: Re: e1000 full-duplex TCP performance well below wire speed Date: Thu, 31 Jan 2008 12:36:27 -0500 Message-ID: <20080131123627.599be68f.billfink@mindspring.com> References: <20080130.055333.192844925.davem@davemloft.net> <20080130082136.1017631d@deepthought> <649aecc70801301617m6331bcb8i8ce60366e182c739@mail.gmail.com> <20080131064533.ef0ae932.billfink@mindspring.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: SANGTAE HA , Linux Kernel Mailing List , netdev@vger.kernel.org, Stephen Hemminger To: Bruce Allen Return-path: Received: from elasmtp-curtail.atl.sa.earthlink.net ([209.86.89.64]:58981 "EHLO elasmtp-curtail.atl.sa.earthlink.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751592AbYAaRge (ORCPT ); Thu, 31 Jan 2008 12:36:34 -0500 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: Hi Bruce, On Thu, 31 Jan 2008, Bruce Allen wrote: > > I see similar results on my test systems > > Thanks for this report and for confirming our observations. Could you > please confirm that a single-port bidrectional UDP link runs at wire > speed? This helps to localize the problem to the TCP stack or interaction > of the TCP stack with the e1000 driver and hardware. Yes, a single-port bidirectional UDP test gets full GigE line rate in both directions with no packet loss. [bill@chance4 ~]$ nuttcp -f-beta -Itx -u -Ru -w2m 192.168.6.79 & nuttcp -f-beta -Irx -r -u -Ru -w2m 192.168.6.79 tx: 1187.0078 MB / 10.04 sec = 992.0550 Mbps 19 %TX 7 %RX 0 / 151937 drop/pkt 0.00 %loss rx: 1187.1016 MB / 10.03 sec = 992.3408 Mbps 19 %TX 7 %RX 0 / 151949 drop/pkt 0.00 %loss -Bill