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

From: Justin Piszcz
Date: Mon Jan 25 2010 - 04:56:15 EST


On Mon, 25 Jan 2010, Justin Piszcz wrote:

Hi,

I think something else may be wrong?

I switched my kernel config to 100 HZ and the problem persists.

So the question remains, is it possible to utilize turbo boost (in Linux)
without the high pitch noise from the ACPI processor module?

Again, when the module is not loaded, no matter what HZ, there is no high pitch noise.

Justin.



Without ACPI processor module loaded, turbo boost never takes effect:

(turbostat)

CPU GHz TSC %c0 %c1 %c3 %c6 %pc3 %pc6 %pc7
0 2.93 2.93 1.41 98.59 0.00 0.00 0.00 0.00 0.00
1 2.93 2.93 100.00 0.00 0.00 0.00 0.00 0.00 0.00
2 2.93 2.93 1.51 98.49 0.00 0.00 0.00 0.00 0.00
3 2.93 2.93 0.97 99.03 0.00 0.00 0.00 0.00 0.00
4 2.93 2.93 0.90 99.10 0.00 0.00 0.00 0.00 0.00
5 2.93 2.93 0.34 99.66 0.00 0.00 0.00 0.00 0.00
6 2.93 2.93 0.40 99.60 0.00 0.00 0.00 0.00 0.00
7 2.93 2.93 3.07 96.93 0.00 0.00 0.00 0.00 0.00

With the module loaded, it works but there is a high pitch noise, again,
only under Linux, when the same benchmark (bzip2 a file) is run under windows
there is no high pitch noise:

CPU GHz TSC %c0 %c1 %c3 %c6 %pc3 %pc6 %pc7
0 3.30 2.93 0.44 0.82 25.29 73.44 0.00 0.00 0.00
1 3.33 2.93 0.24 1.02 25.29 73.44 0.00 0.00 0.00
2 3.43 2.93 1.84 5.41 48.65 44.10 0.00 0.00 0.00
3 3.41 2.93 0.49 6.76 48.65 44.10 0.00 0.00 0.00
4 3.58 2.93 99.44 0.56 0.00 0.00 0.00 0.00 0.00
5 3.43 2.93 0.03 99.97 0.00 0.00 0.00 0.00 0.00
6 3.09 2.93 0.14 0.23 89.74 9.89 0.00 0.00 0.00
7 2.13 2.93 0.01 0.36 89.74 9.89 0.00 0.00 0.00


Justin.


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