Whine when EHCI controller enabled in BIOS

James james at icionline.ca
Mon Jun 9 19:48:53 UTC 2008


On Mon, Jun 9, 2008 at 9:27 AM, Bob McConnell <rvm at cbord.com> wrote:
> On Behalf Of cpghost
>> On Sun, 8 Jun 2008 21:40:17 -0600
>> James <james at icionline.ca> 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.


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