From owner-freebsd-hackers@FreeBSD.ORG Sat Jul 24 23:06:55 2010 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D33081065672; Sat, 24 Jul 2010 23:06:55 +0000 (UTC) (envelope-from mavbsd@gmail.com) Received: from mail-fx0-f54.google.com (mail-fx0-f54.google.com [209.85.161.54]) by mx1.freebsd.org (Postfix) with ESMTP id 8F4118FC12; Sat, 24 Jul 2010 23:06:55 +0000 (UTC) Received: by fxm13 with SMTP id 13so6110651fxm.13 for ; Sat, 24 Jul 2010 16:06:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:sender:message-id:date:from :user-agent:mime-version:to:cc:subject:references:in-reply-to :x-enigmail-version:content-type:content-transfer-encoding; bh=oF/QTcyggo/Ns82j6M4wI8yk7etZ8ON5En1aM9oUpkA=; b=JgX2InMMxUmCy50M0li4wSVWBFOQgfTQRqFmBemIdg/ERUTmQyLJmdZPeBEyk9IJwC 785LsPbFk3AK9DV4krjYI/bP8a8Omj2VaXFDW1lLj2Elmge3R786cE49DvBlVVLIdMCa pken2i8RN6R1hV8XtqpJDfk/B8TXw+hD5Mo8c= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:x-enigmail-version:content-type :content-transfer-encoding; b=SBR0kxHnKeo52rH8kd1eLoMUgmz2/msIEtvxj5e8xMUHB7Ha1+rqfa7wIKhg1I7szy eS/4/Lv0t6GqC7WBqrm/7dfzwuHP0l6mAFCSzmBfET6DjnPiciB/8SKZ9b9wVTnUBhXz AEN707NP/c98DXsjNxjAglJ2aoEPTCBL8BoTo= Received: by 10.223.126.68 with SMTP id b4mr4713168fas.96.1280012814031; Sat, 24 Jul 2010 16:06:54 -0700 (PDT) Received: from mavbook.mavhome.dp.ua (pc.mavhome.dp.ua [212.86.226.226]) by mx.google.com with ESMTPS id r8sm690903faq.10.2010.07.24.16.06.52 (version=SSLv3 cipher=RC4-MD5); Sat, 24 Jul 2010 16:06:53 -0700 (PDT) Sender: Alexander Motin Message-ID: <4C4B720A.6020802@FreeBSD.org> Date: Sun, 25 Jul 2010 02:06:50 +0300 From: Alexander Motin User-Agent: Thunderbird 2.0.0.24 (X11/20100402) MIME-Version: 1.0 To: Rui Paulo References: <4C4AF046.40507@FreeBSD.org> In-Reply-To: X-Enigmail-Version: 0.96.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-hackers@freebsd.org, freebsd-performance@freebsd.org Subject: Re: Intel TurboBoost in practice X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 24 Jul 2010 23:06:56 -0000 Rui Paulo wrote: > On 24 Jul 2010, at 14:53, Alexander Motin wrote: >> Here is my test case: FreeBSD 9-CURRENT on Core i5 650 CPU, 3.2GHz + 1/2 >> TurboBoost steps (+133/+266MHz) with boxed cooler at the open air. I was >> measuring building time of the net/mpd5 from sources, using only one CPU >> core (cpuset -l 0 time make). >> >> Untuned system (hz=1000): 14.15 sec >> Enabled ACPI C2 (hz=1000+C2): 13.85 sec >> Enabled ACPI C3 (hz=1000+C3): 13.91 sec >> Reduced HZ (hz=100): 14.16 sec >> Enabled ACPI C2 (hz=100+C2): 13.85 sec >> Enabled ACPI C3 (hz=100+C3): 13.86 sec >> Timers tuned* (hz=100): 14.10 sec >> Enabled ACPI C2 (hz=100+C2): 13.71 sec >> Enabled ACPI C3 (hz=100+C3): 13.73 sec >> >> All numbers tested few times and are repeatable up to +/-0.01sec. >> >> PS: In this case benefit is small, but it is the least that can be >> achieved, depending on CPU model. Some models allow frequency to be >> risen by up to 6 steps (+798MHz). > > The numbers that you are showing doesn't show much difference. Have you tried buildworld? If you mean relative difference -- as I have told, it's mostly because of my CPU. It's maximal boost is 266MHz (8.3%), but 133MHz of them is enabled most of time if CPU is not overheated. It probably doesn't, as it works on clear table under air conditioner. So maximal effect I can expect on is 4.2%. In such situation 2.8% probably not so bad to illustrate that feature works and there is space for further improvements. If I had Core i5-750S I would expect 33% boost. If you mean absolute difference, here are results or four buildworld runs: hw.acpi.cpu.cx_lowest=C1: 4654.23 sec hw.acpi.cpu.cx_lowest=C2: 4556.37 sec hw.acpi.cpu.cx_lowest=C2: 4570.85 sec hw.acpi.cpu.cx_lowest=C1: 4679.83 sec Benefit is about 2.1%. Each time results were erased and sources pre-cached into RAM. Storage was SSD, so disk should not be an issue. -- Alexander Motin