Under normal operating conditions and with transcoding disabled, ices0 will use next to no CPU time to stream your audio.

The most common cause for high CPU usage in ices0 is enabling stream re-encoding.  Specifically, this includes:

• Turning on cross-fading
• Forcing an specific number of channels or specific sample rate (eg: setting these options to other than 0 in the Centova Cast configuration editor).
  

Using any of the above features can make ices0's CPU usage increase from under 1% to as much as 40-50% (depending on the speed of your server).

The solution to the above problem is to disable the offending features and restart your stream.