Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262494AbUJ0QQa (ORCPT ); Wed, 27 Oct 2004 12:16:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262501AbUJ0QQ3 (ORCPT ); Wed, 27 Oct 2004 12:16:29 -0400 Received: from [195.23.16.24] ([195.23.16.24]:52623 "EHLO bipbip.comserver-pie.com") by vger.kernel.org with ESMTP id S262494AbUJ0QOl (ORCPT ); Wed, 27 Oct 2004 12:14:41 -0400 Message-ID: <417FC96B.8030402@grupopie.com> Date: Wed, 27 Oct 2004 17:14:35 +0100 From: Paulo Marques Organization: Grupo PIE User-Agent: Mozilla Thunderbird 0.7.1 (X11/20040626) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Lee Revell Cc: "Pallipadi, Venkatesh" , Andi Kleen , akpm@osdl.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Add p4-clockmod driver in x86-64 References: <88056F38E9E48644A0F562A38C64FB600333A69D@scsmsx403.amr.corp.intel.com> <417FB7BA.9050005@grupopie.com> <1098892587.8313.5.camel@krustophenia.net> In-Reply-To: <1098892587.8313.5.camel@krustophenia.net> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-AntiVirus: checked by Vexira MailArmor (version: 2.0.1.16; VAE: 6.28.0.11; VDF: 6.28.0.39; host: bipbip) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1825 Lines: 44 Lee Revell wrote: > On Wed, 2004-10-27 at 15:59 +0100, Paulo Marques wrote: > >>I am one of the members of the robotic soccer team from the University >>of Oporto, and a couple of months ago we were looking for new >>motherboards for our robots, because we are starting to need new >>hardware (on-board lan, usb2.0, etc.). >> >>We really don't need excepcional performance, but we really, really need >>low power consumption, so lowering the clock on a standard mainboard >>seemed to be the best cost/performance scenario. >> >>Could this driver be used to keep a standard p4 processor at say 25% >>clock speed at all times? >> > > > Why don't you try the VIA EPIA mini-ITX boards? These are designed for > low power applications like yours. I am running the M-6000 which has a > fanless 600Mhz C3 processor, the newer fanless models run at 1Ghz. And, > on top of that they support speed scaling so you can slow it down even > more. Yes, we tried those, but floating point calculations completely kill the performance on those boards. Even at 25% speed a P4 2.8GHz gives a 700MHz clock which completely toasts a 600MHz (or even a 1GHz) C3 in floating point calculations... :( Even more, I can get a Asus mainboard with integrated VGA, LAN, USB, Audio, for half the price of a VIA EPIA mini-ITX with comparable integer performance. As we always have to buy these things in quantities of 5, this can make some difference. -- Paulo Marques - www.grupopie.com All that is necessary for the triumph of evil is that good men do nothing. Edmund Burke (1729 - 1797) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/