Just to be clear, we're talking about the dancing bars display that appears to the left and right of the song information at the top of the screen. I right clicked and disabled that, then did a few trials. With spectrum analyzer disabled I get:
44.1 Music:
Playing: Less than 4% CPU
Paused: Less than 2% CPU
Stopped: Slightly less than paused, but still between 1 and 2%
1080P Video:
Playing: Just under 40 - 45% CPU
Paused: Less than 3% CPU
Stopped: Less than 2%
That definitely seems to have made a difference. I actually had Spectrum analyzer turned off for a LONG time, but turned it back on as a visual indicator of playback, in the rare instance that my DAC or AMP or whatever wasn't responding. I think I'll just leave it off full time now.
For reference, since Awesome Donkey asked the OP, the JMark on this machine is ~4400 .
Brian.