On 2014-09-30 10:41, Alexander E. Patrakov wrote: > 30.09.2014 14:21, David Henningsson wrote: > >> I did a quick test here. I have an old laptop that runs Ubuntu 12.04, >> with default installed PulseAudio 1.1. Its processor is Intel Pentium M >> @ 1.4 GHz [1], single core, with an AC'97 codec. >> >> Running speaker-test will automatically cause resampling from 48 kHz >> down to 44.1 kHz, as verified with "pactl list sink-inputs". >> >> Under speex-float-1, PulseAudio consumes about 4.3% CPU. With >> speex-float-3, PA consumes ~8% CPU. With speex-float-5, PA consumes ~13% >> CPU. > > OK. Given that Ubuntu provides the SSE2-optimized library for speex on > i386, My CPU seems to include sse2 instructions according to /proc/cpuinfo. Does speex provide both a sse2 and a non-sse2 implementation, and switches dynamically depending on CPU, or is it set at compile time? If the latter, i e, if Ubuntu could only ship one implementation by default, then probably it would choose the non-sse2 version. I think. > I think that our results are comparable. Could you please also > show the actual CPU frequency, if the power-saving features of the > platform allow the kernel to decrease it? Uhm. I just checked /sys/devices/system/cpu/cpu0/cpufreq while speaker-test was running, and it seemed to alternate frequently between 600000, 800000, 1000000, and 1200000. -- David Henningsson, Canonical Ltd. https://launchpad.net/~diwic
