Ripping speed varies by CD but you should be able to get up to 20x from some new CDs if you're not doing anything else. iTunes can hang if it has trouble reading a CD...are they new or old CD you're ripping? If they're old and scratched, this may explain your slow ripping performance. If new, try trashing the iTunes preferences (spotlight "iTunes.plist" and see if that helps. It's rare but occasionally prerefence files can get corrupted.