I have to chip in here as well:
With build 4560 and no USB devices:
- Clean WinXP Pro SP2 siting idle is using 25% CPU. 
- Killing the groove sync process brought the usage down to just under 20%. 
- Disconnecting all shared folders knocked usage down to around 16-17%. 
- Muting the sound brought it down to 12%.
Uninstalling parallels tools and disabling DirectX did not seem to have any effect.
Just for comparison purposes with fusion, a clean xp pro sp2 installation uses around 8% when idle. After following the above steps, playing Pinball in Parallels (without sound) ranged from 40-55% depending on how often I hit the Z and / keys. In fusion Pinball (with sound), usage ranged from 50-60% depending on key activity.
Edit: I have made some corrections to fusion's statistics. Both tests were done in windowed mode with the windows open and visible but not active.
					 
				
			
			
			
		 
		
		
		
			
			
				Last edited: Jul 30, 2007