From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261725AbUB0GU4 (ORCPT ); Fri, 27 Feb 2004 01:20:56 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261707AbUB0GU4 (ORCPT ); Fri, 27 Feb 2004 01:20:56 -0500 Received: from willy.net1.nerim.net ([62.212.114.60]:26887 "EHLO willy.net1.nerim.net") by vger.kernel.org with ESMTP id S261692AbUB0GUx (ORCPT ); Fri, 27 Feb 2004 01:20:53 -0500 Date: Fri, 27 Feb 2004 07:12:20 +0100 From: Willy Tarreau To: MP M Cc: linux-kernel@vger.kernel.org, linux-net@vger.kernel.org Subject: Re: help in TCP checksum offload , TSO and zero copy Message-ID: <20040227061220.GC7785@alpha.home.local> References: <20040226185219.70474.qmail@web21407.mail.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040226185219.70474.qmail@web21407.mail.yahoo.com> User-Agent: Mutt/1.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 26, 2004 at 10:52:19AM -0800, MP M wrote: > ttcp-t: 216442880 bytes in 299.34 real seconds = > 706.13 KB/sec +++ ^^^^^^^^^ It's obvious that you have other problems, because lack of hardware checksum won't lead to such abysmal performance. You should start with *real* traffic, and not with I/O bound tools such as tar. For instance, you'd better use "dd if=/dev/zero bs=64k count=4000" (or use /dev/urandom) to generate some data if you absolutely need some. But here, I'm fairly certain that your disk is *THE* problem. I could easily reach the Gb/s with a P3/1G on a crappy dl2k, so I don't see why you could not to it on better hardware. Oh, and BTW, check your cable (netstat -i) to see if you get drops or errors. You can also have poor wires which lead to frequent retransmits. GigE uses all 4 pairs (8 wires), so a cable which works well on FastEth is not necessarily OK on GigE. Cheers, Willy