From owner-freebsd-questions@FreeBSD.ORG Mon Jun 9 19:48:53 2008 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 1742B106566B for ; Mon, 9 Jun 2008 19:48:53 +0000 (UTC) (envelope-from james@icionline.ca) Received: from wf-out-1314.google.com (wf-out-1314.google.com [209.85.200.168]) by mx1.freebsd.org (Postfix) with ESMTP id EE86D8FC15 for ; Mon, 9 Jun 2008 19:48:52 +0000 (UTC) (envelope-from james@icionline.ca) Received: by wf-out-1314.google.com with SMTP id 24so2128417wfg.7 for ; Mon, 09 Jun 2008 12:48:52 -0700 (PDT) Received: by 10.142.221.19 with SMTP id t19mr1618560wfg.235.1213040932588; Mon, 09 Jun 2008 12:48:52 -0700 (PDT) Received: by 10.142.47.20 with HTTP; Mon, 9 Jun 2008 12:48:52 -0700 (PDT) Message-ID: <7039ada60806091248i270da99et3bed1f7d83d4c387@mail.gmail.com> Date: Mon, 9 Jun 2008 13:48:52 -0600 From: James To: freebsd-questions@freebsd.org In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <7039ada60806082040s36afc2c8n4698402ac5d4ff29@mail.gmail.com> <20080609111200.75197d59@epia-2.farid-hajji.net> Subject: Re: Whine when EHCI controller enabled in BIOS 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: Mon, 09 Jun 2008 19:48:53 -0000 On Mon, Jun 9, 2008 at 9:27 AM, Bob McConnell wrote: > On Behalf Of cpghost >> On Sun, 8 Jun 2008 21:40:17 -0600 >> James wrote: >> >>> I have a high pitched whine coming from my motherboard when the EHCI >>> USB 2.0 controller is enabled in the BIOS. The whine only starts > once >>> FreeBSD 7.0-RELEASE is halfway through booting. >>> >>> The whine also goes away when I plugin a USB drive in with EHCI >>> controller enabled (usb keyboard and mouse being already plugged in). >>> >>> Is this a hardware problem, or could it possibly be software >>> related??? >> >> Hard to tell. I've had whining EPIA-boards when run at 1000 Hz, >> and after switching kern.hz to 100 Hz in /boot/loader.conf, the >> high-pitched whine stopped entirely. It also stopped when I >> slightly deviated from the 1000 Hz (to, say, 900 Hz or 1100 Hz), >> so there was obviously some hardware component on the boards >> oscillating like mad at this very frequency. >> >> I'm no specialist and it may be an urban legend, but from >> what I gathered, some coils could exhibit the behavior of >> generating those high-pitched whines when exposed to certain >> frequencies. >> >> -cpghost. > > No legends here. The horizontal sweep frequency for televisions in the > US is 17,500 Hz. Many people could hear that whistle from cheap flyback > transformers. Other devices would buzz, hum or rattle when they > resonated with EM fields. Occasionally they can be heard by humans, more > frequently they can be heard by their pets. As I have gotten older, I > don't notice it as much. > > Bob McConnell > I think I'm going to just have to try another motherboard unfortunately. The one I'm having problems with is an Asus M2A-VM, which I thought would be good quality. I wonder Gigabyte's all-solid capacitors would make a difference? http://www.gigabyte.com.tw/FileList/NewTech/2006_motherboard_newtech/article_08_ultra_durable2.htm The thing that really bugs me is that it's only there if I don't have certain USB devices plugged in. If I plug in an Apple keyboard and mouse for example (which has usb ports on the keyboard), the noise goes away.