Bought a PC with no soundcard. This works fine on Ubuntu for headphones (haven't tried microphone). I guess the sound quality is not amazing, but through my ordinary headphones it's fine.
(Not sure why, but adjusting the volume is a bit awkward. One step down and there's no sound, one step up and it's very loud. Could be the operating system - just mentioning in case you're buying to use with ubuntu 12.04.)