Re: High pitch noise when ACPI processor module is loaded.

[Justin Piszcz <jpiszcz@lucidpixels.com>]

On Mon, 25 Jan 2010, Ian Campbell wrote:

> On Mon, 2010-01-25 at 04:26 -0500, Justin Piszcz wrote:
>> So the question remains, is it possible to utilize turbo boost (in Linux)
>> without the high pitch noise from the ACPI processor module?
>
> I have to use the max_cstate=2 option to processor.ko in order to not
> have a similar high pitch noise. I suppose you might get away higher
> values of max_cstate depending on your hardware. Battery life doesn't
> seem to be too adversely impacted.

Hello,

I tried this, but then the max speed bin is only 3.2GHz instead of 3.6GHz,
it does solve the problem but limits the CPU quite a bit, see below:

  CPU   GHz    TSC    %c0    %c1    %c3    %c6   %pc3   %pc6   %pc7
    0   3.20   2.93   0.33  99.67   0.00   0.00   0.00   0.00   0.00
    1   3.20   2.93   0.09  99.91   0.00   0.00   0.00   0.00   0.00
    2   3.20   2.93 100.00   0.00   0.00   0.00   0.00   0.00   0.00
    3   3.20   2.93   0.95  99.05   0.00   0.00   0.00   0.00   0.00
    4   3.20   2.93   0.08  99.92   0.00   0.00   0.00   0.00   0.00
    5   3.20   2.93   0.02  99.98   0.00   0.00   0.00   0.00   0.00
    6   3.20   2.93   0.06  99.94   0.00   0.00   0.00   0.00   0.00
    7   3.20   2.93   0.01  99.99   0.00   0.00   0.00   0.00   0.00

--

It would be nice if it were possible to find out what is causing it exactly
in the acpi cpufreq module, as this problem does not occur in Windows 7 and
I can achieve 3.6GHz in Windows 7 w/out any high pitch noise.

Justin.