On Mon, Jun 9, 2008 at 9:27 AM, Bob McConnell <[EMAIL PROTECTED]> wrote: > On Behalf Of cpghost >> On Sun, 8 Jun 2008 21:40:17 -0600 >> James <[EMAIL PROTECTED]> 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. _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
