I am running Gentoo Linux Kernel 3.2.1-gentoo-r2 x86_64 AMD A8-3500M APU with mumble 1.2.3-r2 + pulseaudio
and just noticed a cpu usage of 15 - 20% when it should be idle, even without echo cancellation it's about 10%.
After searching for mumble+high+cpu i came over this forums post:
"Because of certain circumstances i have to use Mumble on my notebook running Ubuntu. But the CPU usage (even idle) is unaccaptable for me: ~10% mumble ~10% pulseaudio This shortens the runtime of my battery, increases noise and heat, unnacessarily! So I took a look on the well structured but completely uncommented source (SHAME, not interested in others understanding their code? ) After adding few lines here and there the CPU usage (idle) dropped to 1% mumble 1% pulseaudio Thats 90% idle (up to 50% talking) without quality or latency loss . My personal opinion is that it is even better than before. I can even switch between my power saving option and the default one without restarting mumble. Its really a shame. That blah blah for high end gamer pc blah blah Quality blah blah is a weak pretext. Bad for environment too. Using up to 10W on each machine its used on for idling?"
"I simply added a real idle mode (for sending and receiving seperately) while preserving the preprocessing settings. So there is no full up/down stream even when nothing happens. A "real" bug is perhaps the sudden cut off when using push-to-talk, so i added a tolerace there. I guess it is ignoring the latency or maybe it my slower notebook hardware. Now it works fine. Its a quick and dirt fix because there are no commemts and i dont have the time to read through all the code and try to figure out what it is doing. (+ compile difficulties with added class functions)"
After realizing that this behavior did not change since over one year i thought now it's time to do something!