iTunes on Mac OS X 10.5 is consistently using 10-11% of the cpu when playing one song. I understand that iTunes is a resource hog and my iTunes library is pretty big but could any other programs be acting on it, or are there any steps I can take to reduce the cpu usage?
iTunes uses about 6% CPU on my 2.4 GHz Core 2 Duo to play a 238 kbs (VBR) MP3. But, so does VLC playing the same song. Playing the song from the command line with Sox takes about 3%. It seems reasonable to me, decoding compressed music is not free.
!0% could be about right on a slower processor. My G4 is unavailable for comment right now.
Visualizer takes a lot of CPU. Equalizer adds a percent or so, as well.