[alsa-devel] opengl 'leaking' sound to input.

dE de.techno at gmail.com
Thu Oct 30 16:46:08 CET 2014


On 10/30/14 16:00, Clemens Ladisch wrote:
> dE wrote:
>> I'm trying to record audio from the analog input device of my card,
>> but whenever there seems to be some graphics intensive activity like
>> glxgears, OpenGL assisted window manager, audacity graphs etc...
>> a noise appears in the recording which sounds like some kind of
>> sparking disturbance.
> Sudden changes in power consumption will affect the voltage on the
> power lines.  (If the GPU is powered only from the mainboard, there is
> not much your PSU could do against this.)  Your card (whatever it is)
> apparently is not properly isolated against such fluctuations.
>
>
> Regards,
> Clemens

The GPU takes very less power (motherboard embedded), in contrast the 
CPU takes 80W and usually it'll take at least 15W (CPU scaling).

But with the CPU fluctuations, there's no nose. It has to do only with 
OpenGL. If I try VESAfb with software OpenGL, there's no noise.


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