From owner-freebsd-amd64@FreeBSD.ORG Fri Mar 12 10:25:33 2004 Return-Path: Delivered-To: freebsd-amd64@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id F193316A4D0 for ; Fri, 12 Mar 2004 10:25:32 -0800 (PST) Received: from canning.wemm.org (canning.wemm.org [192.203.228.65]) by mx1.FreeBSD.org (Postfix) with ESMTP id DF53543D41 for ; Fri, 12 Mar 2004 10:25:32 -0800 (PST) (envelope-from peter@evilpete.dyndns.org) Received: from fw.wemm.org (canning.wemm.org [192.203.228.65]) by canning.wemm.org (Postfix) with ESMTP id A91602A928 for ; Fri, 12 Mar 2004 10:25:32 -0800 (PST) (envelope-from peter@overcee.wemm.org) Received: from overcee.wemm.org (overcee.wemm.org [10.0.0.3]) by fw.wemm.org (Postfix) with ESMTP id E84D1E259 for ; Fri, 12 Mar 2004 10:25:31 -0800 (PST) (envelope-from peter@overcee.wemm.org) Received: from overcee.wemm.org (localhost [127.0.0.1]) by overcee.wemm.org (8.12.11/8.12.10) with ESMTP id i2CIPTQK077068; Fri, 12 Mar 2004 10:25:29 -0800 (PST) (envelope-from peter@overcee.wemm.org) Received: from localhost (localhost [[UNIX: localhost]]) by overcee.wemm.org (8.12.11/8.12.10/Submit) id i2CIPSOZ077067; Fri, 12 Mar 2004 10:25:28 -0800 (PST) (envelope-from peter) From: Peter Wemm To: freebsd-amd64@freebsd.org Date: Fri, 12 Mar 2004 10:25:28 -0800 User-Agent: KMail/1.6 References: <4051A841.9020205@thejemreport.com> In-Reply-To: <4051A841.9020205@thejemreport.com> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200403121025.28913.peter@wemm.org> cc: Jem Matzan Subject: Re: Peer review of AMD64/FreeBSD article X-BeenThere: freebsd-amd64@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Porting FreeBSD to the AMD64 platform List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 12 Mar 2004 18:25:33 -0000 On Friday 12 March 2004 04:08 am, Jem Matzan wrote: > I've just finished writing this article comparing performance between > an Athlon64 in 32-bit and 64-bit mode using FreeBSD: > > http://www.thejemreport.com/lab64/amd64vsi386.php > > (this is a temporary address which will later redirect to the > published article) > > I've checked it over twice for fact accuracy, but I would like other > eyes to look at it before it goes to press. I haven't spell-checked > it yet, so don't worry about that... I just want to make sure I > haven't made any factual errors. There's a couple of quick comments I'd like to make. The OpenSSL stuff in the FreeBSD source tree has hand-optimized i386 assembler code in it. The amd64 configuration of the integrated OpenSSL uses the generic C code. Given this, I wouldn't expect them to be even close. In the Stream section, you mention that the P4 has a faster front-side-bus.. Faster than what? The AMD64 system doesn't have a frontside bus inbetween the cpu and memory. The big difference though is that your AMD64 machine has a single 3.2GB/sec max memory controller, while the P4 has a dual-channel memory controller. In other words, the AMD64 machine is getting half of the memory bandwidth of the P4 due to the DIMM configuration. I'd be interested to see what happens if you compared the dual-channel Pentium-4 configuration to a dual-channel Athlon-FX, or a single channel Pentium-4 configuration to a single channel Athlon64. I'd be fascinated to see what happened if you ran a second set of tests with a single memory DIMM for a more level playing field. At the very least you should make a mention of this. It should be rather interesting to point out that the single-channel athlon64 had the upper hand in those tests compared to the dual-channel configuration P4. -- Peter Wemm - peter@wemm.org; peter@FreeBSD.org; peter@yahoo-inc.com "All of this is for nothing if we don't go to the stars" - JMS/B5