From owner-freebsd-acpi@FreeBSD.ORG Thu May 25 15:03:48 2006 Return-Path: X-Original-To: freebsd-acpi@freebsd.org Delivered-To: freebsd-acpi@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 6926816A57C for ; Thu, 25 May 2006 15:03:48 +0000 (UTC) (envelope-from avg@icyb.net.ua) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.FreeBSD.org (Postfix) with ESMTP id 93F1143D46 for ; Thu, 25 May 2006 15:03:46 +0000 (GMT) (envelope-from avg@icyb.net.ua) Received: from [212.40.38.87] (oddity-e.topspin.kiev.ua [212.40.38.87]) by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id SAA25126; Thu, 25 May 2006 18:03:40 +0300 (EEST) (envelope-from avg@icyb.net.ua) Message-ID: <4475C74C.2080204@icyb.net.ua> Date: Thu, 25 May 2006 18:03:40 +0300 From: Andriy Gapon User-Agent: Thunderbird 1.5.0.2 (X11/20060512) MIME-Version: 1.0 To: freebsd-acpi@freebsd.org Content-Type: text/plain; charset=KOI8-U Content-Transfer-Encoding: 7bit Cc: Nate Lawson Subject: nforce2 cpufreq X-BeenThere: freebsd-acpi@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: ACPI and power management development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 25 May 2006 15:03:51 -0000 I've recently had a sudden urge to investigate power saving / cpu throttling options for my desktop Athlon XP system. It seems that the CPU itself does not provide any interfaces for that, at least neither of acpi_perf/acpi_throttle/cpufreq seem to detect anything interesting for them. Or am I mistaken and doing something wrong ? Anyway, my MB is based on nForce2 chipset and I found out that Linux has cpufreq-nforce2 module that works in their cpufreq framework: http://www.hasw.net/linux/ It seems that that module works by using nForce2 PCI interface for querying and changing FSB frequency. It also seems that the code is rather simple and obvious in its logic (save for allegedly reverse-engineered constants). Not sure though how easy it is to port that to FreeBSD cpufreq framework. But the question that I really would like to ask is the following: is it a proper way to do cpufreq stuff by changing FSB frequency ? Would that approach fit into our framework ? And finally, would it have any positive temperature/power consumption effects ? -- Andriy Gapon