From owner-freebsd-current@FreeBSD.ORG Fri Sep 21 19:33:40 2007 Return-Path: Delivered-To: freebsd-current@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 9A71516A41A for ; Fri, 21 Sep 2007 19:33:40 +0000 (UTC) (envelope-from jdc@parodius.com) Received: from mx01.sc1.parodius.com (mx01.sc1.parodius.com [72.20.106.3]) by mx1.freebsd.org (Postfix) with ESMTP id 7B44713C480 for ; Fri, 21 Sep 2007 19:33:40 +0000 (UTC) (envelope-from jdc@parodius.com) Received: by mx01.sc1.parodius.com (Postfix, from userid 1000) id 51D561CC02B; Fri, 21 Sep 2007 12:33:40 -0700 (PDT) Date: Fri, 21 Sep 2007 12:33:40 -0700 From: Jeremy Chadwick To: Chuck Swiger Message-ID: <20070921193340.GA70365@eos.sc1.parodius.com> Mail-Followup-To: Chuck Swiger , Rui Paulo , Doug Barton , Alexander Leidinger , Shteryana Shopova , FreeBSD Current , "Constantine A. Murenin" References: <200709132302.l8DN2Tv5076033@repoman.freebsd.org> <46E9FC0C.70607@FreeBSD.org> <46F1A96F.2040602@FreeBSD.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.16 (2007-06-09) Cc: Rui Paulo , Doug Barton , "Constantine A. Murenin" , Shteryana Shopova , FreeBSD Current , Alexander Leidinger Subject: Re: GSoC2007: cnst-sensors.2007-09-13.patch X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 21 Sep 2007 19:33:40 -0000 On Fri, Sep 21, 2007 at 12:20:07PM -0700, Chuck Swiger wrote: > The CPU itself has a thermal control circuit which puts the CPU into a > reduced duty cycle (ie, it reduces the core voltage and stops the CPU for > something like 10 clocks, and then allows one clock through) and continues > to run the CPU at about 10% of normal workload until the temperature falls > below the critical threshold. There's a good document here: Are you referring to the Core 2 Duo C1E (Enhanced Halt State) processor feature or the EIST feature? I'm guessing C1E. Note that for C1E to work, it has to be enabled/available in the BIOS. I'll add that C1E is really great, dropping temperatures during idle periods by about 5-6C from what I've seen. The additional C[234]E states (at least for desktops) don't provide much benefit, but C1E definitely does. -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |