From owner-freebsd-questions@FreeBSD.ORG Thu Jun 15 20:20:51 2006 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id BF31616A41A for ; Thu, 15 Jun 2006 20:20:51 +0000 (UTC) (envelope-from pm940@yahoo.com) Received: from web54005.mail.yahoo.com (web54005.mail.yahoo.com [206.190.36.229]) by mx1.FreeBSD.org (Postfix) with SMTP id 4AF4A43D46 for ; Thu, 15 Jun 2006 20:20:51 +0000 (GMT) (envelope-from pm940@yahoo.com) Received: (qmail 14312 invoked by uid 60001); 15 Jun 2006 20:20:50 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:Received:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding; b=6qDO0Y/3QFdIJTGg2Mc6gIMFlr+kSlegP0glKe0EscWmPDsOIuHrlh40GpAuX3YAWFc5zFDmnrxSYsusynOcF1N0QW/0Wco6d3p9z4lM3dYB/z/d6xPqhZ4BOE82YHZ/rQqk4Pb5nK1PkZQPFfNUyah9NDbPDKLLMJmC9nFl7bc= ; Message-ID: <20060615202050.14310.qmail@web54005.mail.yahoo.com> Received: from [71.140.186.33] by web54005.mail.yahoo.com via HTTP; Thu, 15 Jun 2006 13:20:50 PDT Date: Thu, 15 Jun 2006 13:20:50 -0700 (PDT) From: Paul Marciano To: danial_thom@yahoo.com, freebsd-questions@freebsd.org In-Reply-To: <20060615195851.34041.qmail@web33314.mail.mud.yahoo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Cc: Subject: Re: fxp driver performance expectations X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 15 Jun 2006 20:20:51 -0000 --- Danial Thom wrote: > You couldn't do 100Mb/s with em on a 100Mb/s line > with min packets, because there are gaps between > packets so its impossible. Thanks for the detailed reply Danial. By 100Mbps I mean line-rate: 148809 packets/sec for 64-byte Ethernet frames + IPG and preamble appended. The 10/100 fxp NIC is on straight PCI-33. The 1000 em NIC is on PCI-Express x1. It can do 100Mbps line-rate (148809pps) in 100Mbps mode. In 1000Mbps mode it can do ~700Kpps, so the bottleneck isn't the FreeBSD IP stack. > Realize that fxp parts are only 32bit/33mhz so > the bus is a factor. Although its a 1Gb/s bus, > thats only when bursting, so its really > substantially less. With shorter packets you > have more setups and I/O and therefore more > overhead on the bus. Yes indeed. > fxp performs similarly to an em controller when > they are both on a 32bit/33mhz bus in Freebsd 4.x. > 5.x is about 20% slower than 4.x, but I expect the > drivers to be about the same for 5.x as well. Thanks for that. I realize that comparing a PCI-33 NIC to a PCI-Express NIC isn't fair. I don't have a PCI-33 Gig NIC - why I need outside info. > Are you using a traffic generator, or are you > relying on some server to return packets? Ixia traffic generator. > We have customers with fxp interfaces on freebsd > 4.x pushing 90Mb/s+ (while doing a lot of other > processing also), so its certainly possible. Yes, I can get 100Mbps using larger frames on the fxp - but it's the performance limit on the smallest frames, with the largest per-frame overhead, that I'm trying to discover. Thanks again for the reply - I appreciate the info. Paul. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com