From owner-freebsd-current@FreeBSD.ORG Mon Mar 12 19:15:41 2012 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 41F99106564A; Mon, 12 Mar 2012 19:15:41 +0000 (UTC) (envelope-from mavbsd@gmail.com) Received: from mail-bk0-f54.google.com (mail-bk0-f54.google.com [209.85.214.54]) by mx1.freebsd.org (Postfix) with ESMTP id 94C7E8FC0C; Mon, 12 Mar 2012 19:15:40 +0000 (UTC) Received: by bkcjc3 with SMTP id jc3so4029250bkc.13 for ; Mon, 12 Mar 2012 12:15:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:message-id:date:from:user-agent:mime-version:to:subject :content-type:content-transfer-encoding; bh=DPnVeo72CVNO9h/ofo6oWjVDM69/REysPmBSqzAA/uI=; b=y2H+TmTekSKmA+9c3BGu5cvsQ83Yl2DSja/Ls7WFh78UUC0faantVWdKsD0Bg49qOV CXTdUcsKLu91qms7ITQbx/NHegWuI6YKe5gKn0FtibKGnuTgMWd45COK+ieQCV0ilZ0I HdaKoai2//9YTKYDn2RPY7pM+HKvOKL/dXbT8o5bhms6xtFcRMl+Kn3nwMNSJGdyGQeC bomxAemQ5JuH7yMIC3ltMOlUr7fggzNV6Z3NGFm44gOSCLVgDoo+vH+40LyKriuBMznP ym1WUEOf5f7mDJzXuqUvSUMUCC7ndeoUglb1RGcs9tlonawiKFT+zQHn4QvcDbH07jxq fB/A== Received: by 10.204.9.205 with SMTP id m13mr5148300bkm.68.1331579739574; Mon, 12 Mar 2012 12:15:39 -0700 (PDT) Received: from mavbook2.mavhome.dp.ua (pc.mavhome.dp.ua. [212.86.226.226]) by mx.google.com with ESMTPS id h16sm27293854bkk.12.2012.03.12.12.15.36 (version=SSLv3 cipher=OTHER); Mon, 12 Mar 2012 12:15:37 -0700 (PDT) Sender: Alexander Motin Message-ID: <4F5E4B57.1050605@FreeBSD.org> Date: Mon, 12 Mar 2012 21:15:35 +0200 From: Alexander Motin User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:10.0.2) Gecko/20120226 Thunderbird/10.0.2 MIME-Version: 1.0 To: FreeBSD current , freebsd-performance@FreeBSD.org Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Subject: Improved Intel Turbo Boost status/control 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: Mon, 12 Mar 2012 19:15:41 -0000 Hi. I'd like to note that recent r232793 change to cpufreq(4) in HEAD opened simple access to the Intel Turbo Boost status/control. I've found that at least two of my desktop systems (based Nehalem and SandyBridge Core i7s) with enabled Intel Turbo Boost in BIOS it is not use it by default, unless powerd is enabled. And before this change it was difficult to detect/fix. ACPI reports extra performance level with frequency 1MHz above the nominal to control Intel Turbo Boost operation. It is not a bug, but feature: dev.cpu.0.freq_levels: 2934/106000 2933/95000 2800/82000 ... In this case value 2933 means 2.93GHz, but 2934 means 3.2-3.6GHz. After boot with default settings I see: dev.cpu.0.freq: 2933 , that means Turbo Boost is disabled. Enabling powerd or just adding to rc.conf performance_cpu_freq="HIGH" enables Turbo Boost and adds extra 10-20% to the system performance. Turbo Boost operation can be monitored in run-time via the PMC with command that prints number or really executed cycles per CPU core: pmcstat -s unhalted-core-cycles -w 1 -- Alexander Motin