From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Henriot Subject: understanding acpi Date: Thu, 30 Nov 2006 11:55:16 +0100 Message-ID: <456EB894.20306@imag.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from imag.imag.fr ([129.88.30.1]:35014 "EHLO imag.imag.fr") by vger.kernel.org with ESMTP id S935663AbWK3K7O (ORCPT ); Thu, 30 Nov 2006 05:59:14 -0500 Received: from [192.168.1.101] (lns-bzn-23-82-248-109-151.adsl.proxad.net [82.248.109.151]) by imag.imag.fr (8.13.6/8.13.6) with ESMTP id kAUAsfPN016577 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Thu, 30 Nov 2006 11:54:46 +0100 (CET) Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: linux-acpi@vger.kernel.org Hi all list subscribers, I'm looking for info on how acpi functions in order to get it to work the best possible on my computer. It's a Sony laptop (vaio vgn-sz3xp/c, core2duo) running Debian Etch. In particular, I'm looking for ways to reduce thermal dissipation from the CPU as much as possible, in order to queep the machine as quiet as possible. From the various docs I've read, so far I seem to understand that C-states is the way to go, throttling being probably not very efficient. When I'm running on batteries, C3 state is active (as shown by cat /prc/acpi/processor/CPU0/power) and is the main state, whereas when I'm running on mains, C3 disappears and only C1 and C2 remain. My question are : wouldn't it be better if I could use C3 even when on mains. Wouldn't it be even better with C4? As suggested by "Why My Cx Power State Is Not Used" I tried unloading various modules (e.g. those concerning usb but I got stuck with usbcore which refused to unload despite nothing usb being connected) without any success. Being relatively new to GNU/Linux, I'm a bit stuck here and don't know where to look or what to make of this. Any help would be gladly welcome. Cheers, Oliver