pulseaudio CPU usage and process name

Lennart Poettering mzerqung at 0pointer.de
Fri Nov 16 21:22:43 UTC 2007


On Fri, 16.11.07 21:57, Ahmed Kamal (email.ahmedkamal at googlemail.com) wrote:

> Hi,
> Thanks for the reply. I can confirm terminating firefox brought CPU usage of
> pulseaudio down to 0% in top. Also, playing an mp3 through amarok, brought
> CPU usage back to 6%. So it seems any playback brings the CPU usage up by
> that much!
> My sound card is Intel ICH6 chipset ALC861. Is resampling required ? Is it
> possible to play at the card's native sample rate to gain back the CPU
> cycles, since I almost always have the browser open with Flash in it :/

Flash is fixed to 44100 Hz. Apparently your card is fixed to 48000
Hz (you can check by running "pacmd" and typing "list-sinks"). So, in
effect resampling is *required* to take place. There's no way around
it. 

I wouldn't really think about this much. Don't forget, if PA wouldn't
do the resampling the player (or libasound) would need to do it. So
it's just a shuffling of which process does which job that make PA eat
6% CPU.

If you feel that the resampling takes to much CPU, than you're welcome
to sit down and add some real MMX/SSE support to the speex resampler,
which is the one we're using. ;-)

Lennart

-- 
Lennart Poettering                        Red Hat, Inc.
lennart [at] poettering [dot] net         ICQ# 11060553
http://0pointer.net/lennart/           GnuPG 0x1A015CC4




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