From owner-freebsd-hackers@FreeBSD.ORG Fri Aug 1 01:27:10 2003 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 0534337B401 for ; Fri, 1 Aug 2003 01:27:09 -0700 (PDT) Received: from mail.cyberonic.com (mail.cyberonic.com [4.17.179.4]) by mx1.FreeBSD.org (Postfix) with ESMTP id 1360B43FB1 for ; Fri, 1 Aug 2003 01:27:09 -0700 (PDT) (envelope-from jmg@hydrogen.funkthat.com) Received: from hydrogen.funkthat.com (node-40244c0a.sfo.onnet.us.uu.net [64.36.76.10]) by mail.cyberonic.com (8.12.8/8.12.5) with ESMTP id h718xu0n021950; Fri, 1 Aug 2003 04:59:56 -0400 Received: (from jmg@localhost) by hydrogen.funkthat.com (8.12.9/8.11.6) id h718QwMA087236; Fri, 1 Aug 2003 01:26:58 -0700 (PDT) (envelope-from jmg) Date: Fri, 1 Aug 2003 01:26:58 -0700 From: John-Mark Gurney To: Ruben de Groot , mh , freebsd-hackers@freebsd.org Message-ID: <20030801082658.GQ10708@funkthat.com> Mail-Followup-To: Ruben de Groot , mh , freebsd-hackers@freebsd.org References: <200307311219.h6VCJLVG053962@spider.deepcore.dk> <3F29D164.6090904@nerim.net> <20030801081503.GA66987@ei.bzerk.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030801081503.GA66987@ei.bzerk.org> User-Agent: Mutt/1.4.1i X-Operating-System: FreeBSD 4.2-RELEASE i386 X-PGP-Fingerprint: B7 EC EF F8 AE ED A7 31 96 7A 22 B3 D8 56 36 F4 X-Files: The truth is out there X-URL: http://resnet.uoregon.edu/~gurney_j/ X-Resume: http://resnet.uoregon.edu/~gurney_j/resume.html Subject: Re: Ultra ATA card doesn't seem to provide Ultra speeds. X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: John-Mark Gurney List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 01 Aug 2003 08:27:10 -0000 Ruben de Groot wrote this message on Fri, Aug 01, 2003 at 10:15 +0200: > On Fri, Aug 01, 2003 at 04:33:08AM +0200, mh typed: > The following comparison is probably bogus, but can anybody explain the > huge difference? It's called micro optimization. Linux feels the need to special case /dev/zero to /dev/null, and instead of even reading/writing the data, It just ignores the user request, (or does something like set the pages in the user space to be zero'd. Also, dual procs won't help your performance when you run a single process like this. So your are still comparing a 1ghz P3 to a 2.6ghz p4 which isn't even being close to fare. I have a P4 that out runs my 386, why? :) -- John-Mark Gurney Voice: +1 415 225 5579 "All that I will do, has been done, All that I have, has not."