From owner-freebsd-stable@FreeBSD.ORG Thu Mar 22 09:51:30 2012 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id B7CDF106564A for ; Thu, 22 Mar 2012 09:51:30 +0000 (UTC) (envelope-from alexander@leidinger.net) Received: from mail.ebusiness-leidinger.de (mail.ebusiness-leidinger.de [217.11.53.44]) by mx1.freebsd.org (Postfix) with ESMTP id 5A5AA8FC14 for ; Thu, 22 Mar 2012 09:51:30 +0000 (UTC) Received: from outgoing.leidinger.net (p4FC4315E.dip.t-dialin.net [79.196.49.94]) by mail.ebusiness-leidinger.de (Postfix) with ESMTPSA id E38BE844846; Thu, 22 Mar 2012 10:51:16 +0100 (CET) Received: from webmail.leidinger.net (webmail.Leidinger.net [IPv6:fd73:10c7:2053:1::3:102]) by outgoing.leidinger.net (Postfix) with ESMTPS id 2FA09252C; Thu, 22 Mar 2012 10:51:14 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=leidinger.net; s=outgoing-alex; t=1332409874; bh=9BeMJRia13g+iB5310b4tq18b4Jsp2iSOD3PQjMtBVI=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=PMW2yOFNGA263dr13Gt9G7bsPZDmRKsYFu86DlNNDz4zmwgQ1oaAyMX+NDzngmtXj 4J+eMUlGZ4RjK1MSUEMqHPfvO9oq7LXvPH17F7AQ7qyvX3d2h3Os7cSxpYr2jV/JeF kkhexbpTL/BHCv4EX42rdzI7n/Q69OMZgs6+ayQ48cD4eo3uVJQAHVHniWcNelyNbk PrAGHR2nTx2t47ljUHPVzZXLxh7QMQC9aEH9PzZKTeWCyQSg5CU4r3JK3o78ocR6hZ tw89flTQ04gfR6DCOmCZbk/urnWgar7hRf5M75ArsYv206xX5S220HmrLNAKN7Uvg5 VJHgNWBPj6MFQ== Received: (from www@localhost) by webmail.leidinger.net (8.14.5/8.14.4/Submit) id q2M9pCJs046311; Thu, 22 Mar 2012 10:51:12 +0100 (CET) (envelope-from Alexander@Leidinger.net) X-Authentication-Warning: webmail.leidinger.net: www set sender to Alexander@Leidinger.net using -f Received: from 195.46.238.194 ([195.46.238.194]) by webmail.leidinger.net (Horde Framework) with HTTP; Thu, 22 Mar 2012 10:51:12 +0100 Date: Thu, 22 Mar 2012 10:51:09 +0100 Message-ID: <20120322105109.Horde.srohf5jmRSRPavYNP_frKBA@webmail.leidinger.net> From: Alexander Leidinger To: Luigi Rizzo References: <20120321000058.177F8256@server.theusgroup.com> <20120321173728.GA41322@onelab2.iet.unipi.it> In-Reply-To: <20120321173728.GA41322@onelab2.iet.unipi.it> User-Agent: Internet Messaging Program (IMP) H4 (5.0.19) Content-Type: text/plain; charset=ISO-8859-1; format=flowed; DelSp=Yes MIME-Version: 1.0 Content-Disposition: inline X-EBL-MailScanner-Information: Please contact the ISP for more information X-EBL-MailScanner-ID: E38BE844846.A2B44 X-EBL-MailScanner: Found to be clean X-EBL-MailScanner-SpamCheck: not spam, spamhaus-ZEN, SpamAssassin (not cached, score=-0.806, required 6, autolearn=disabled, AWL -0.70, DKIM_SIGNED 0.10, DKIM_VALID -0.10, DKIM_VALID_AU -0.10, T_RP_MATCHES_RCVD -0.01) X-EBL-MailScanner-From: alexander@leidinger.net X-EBL-MailScanner-Watermark: 1333014677.79888@E+RcCm+EkcXW9t2SPHYeiw X-EBL-Spam-Status: No Cc: Matthias Gamsjager , freebsd-stable@freebsd.org, John Subject: Re: powerd and increase in energy need X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 22 Mar 2012 09:51:30 -0000 Quoting Luigi Rizzo (from Wed, 21 Mar 2012 18:37:28 +0100): > I guess that the credit for power saving goes mostly to the CPU > architects. Powerd only gives second-order savings, and C1 vs. C3 > is ineffective, at least for HZ=1000 > > CPU Power (watts) > freq idle 16 threads > ----------------------- > 200 48 51 > 2200 52 83 > 3200 54 115 > 3401 56 118 > > powerd 48 118 I hope you all don't use a cheap PSU, but a _good_ high efficient one, which really draws less power when idle instead of generating heat. Some PSUs are only efficient in a sweet spot, instead of being efficient over a broad range, even when being idle. See http://en.wikipedia.org/wiki/80_PLUS for a quick and not so in-deep overview (and the reality may differ from manufacturer to manufacturer). Bye, Alexander. -- That does not compute. http://www.Leidinger.net Alexander @ Leidinger.net: PGP ID = B0063FE7 http://www.FreeBSD.org netchild @ FreeBSD.org : PGP ID = 72077137