From owner-freebsd-questions@FreeBSD.ORG Sun Jul 1 13:46:26 2007 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 006BC16A400 for ; Sun, 1 Jul 2007 13:46:25 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from pi.codefab.com (pi.codefab.com [199.103.21.227]) by mx1.freebsd.org (Postfix) with ESMTP id C92C613C46A for ; Sun, 1 Jul 2007 13:46:25 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from localhost (localhost [127.0.0.1]) by pi.codefab.com (Postfix) with ESMTP id D39E95ED3; Sun, 1 Jul 2007 09:46:24 -0400 (EDT) X-Virus-Scanned: amavisd-new at codefab.com Received: from pi.codefab.com ([127.0.0.1]) by localhost (pi.codefab.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id vmQpcXY+SV95; Sun, 1 Jul 2007 09:46:21 -0400 (EDT) Received: from [192.168.1.110] (pool-96-224-41-41.nycmny.east.verizon.net [96.224.41.41]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by pi.codefab.com (Postfix) with ESMTP id 3F3515C8D; Sun, 1 Jul 2007 09:46:21 -0400 (EDT) Message-ID: <4687B02B.7080106@mac.com> Date: Sun, 01 Jul 2007 09:46:19 -0400 From: Chuck Swiger User-Agent: Thunderbird 1.5.0.12 (Windows/20070509) MIME-Version: 1.0 To: cpghost References: <46878C1C.9040907@cordula.ws> In-Reply-To: <46878C1C.9040907@cordula.ws> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: questions Subject: Re: kern.hz="100" stops high-pitched whine X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 01 Jul 2007 13:46:26 -0000 cpghost wrote: > Are there any reasons NOT changing kern.hz from the > default 1000 back to 100? With my typical mix of > desktop apps (EPIA) and networking / server (Soekris), > everything seems to be running just as smoothly with > 100 Hz than with 1000 Hz (testing now for two weeks > without problems). Even playing videos with mplayer > on the EPIA doesn't look different in any way. > > Is it okay to stay with 100 Hz with this type of > low-speed CPU/boards? Or are there some compelling > reasons not to? Actually, many Unix systems ran with HZ=100 until a few years ago, about when Gb ethernet and CPUs became common. A slower machine like the EPIA boxes do quite well with HZ=100/200/250 or so...HZ=1000 is better if you have a fast box running lots of concurrent processes, and/or are proxying or routing network traffic where the difference between 10 ms and 1ms of latency adds up and/or effects other systems. -- -Chuck