If it's a dedicated (HT)PC and no other power draining processes are running, it's definately way too much CPU load for music-only playback. My ~3 year old and by no means (even at the time) CPU-powerful HTPC runs at 0% with music playback, with the rare occasional 1% peak or momentary ~10% peak at the time of loading a new track onto RAM(memory playback).
Is the 11% CPU load constant, at all times with music playback? I'm hoping for others to come up with possible solutions to this...