0.4 Watt Less During Audio Playback - (Updated:) Power Performance: Pulseaudio + Interrupt-Less Alsa

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Ok, so with some help from Pierre-Louis from Intel I've managed to get it working and do some performance/power tests. But let me start at the beginning: Recently, pulseaudio not only switched to a more power efficient (and otherwise) timing system, as far as I understand a callback API. It also provided the infrastructure to use ALSA devices without causing any interrupts ("period wakeup disabling"), so you CPU can stay longer in standby mode (e.g. "C6 residency"), saving you power and avoiding playback glitches at the same time. See here and here or more background information. With kernel 2.6.38 the first driver (snd-hda-intel) supports this infrastructure out of the box, the snd-hda-intel driver. This combination is what I tested for power efficiency...
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