previous versions of ubuntu I dont see %10 cpu usage by sound system. But that Pulse audio uses much both memory and cpu.
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
6328 nerkn 20 0 310m 46m 16m S 16 2.3 44:28.11 chrome
13602 nerkn 9 -11 157m 7948 6896 S 9 0.4 0:14.10 pulseaudio
7930 nerkn 20 0 314m 37m 13m S 7 1.8 46:10.29 rhythmbox
1087 root 20 0 127m 35m 16m S 3 1.8 604:28.55 Xorg
13551 nerkn 20 0 2548 1152 840 R 1 0.1 0:01.58 top
1505 nerkn 20 0 98.2m 9184 5228 S 1 0.4 13:23.48 clock-applet
I think, every achivement new program infact a replacement of old working one with buggy, memory, cpu monster. Except that why a basic mp3 streaming consumes %16 cpu?!