Some programs allow you to chose (like LOTRO and so on, and normal windows sound settings, but only if those drivers does not conflict with each other, and guite often they does, but still you only get one output at the time... You can switch between them though... I have SB X-fi and SB usb sound devise in my system and they do work together, but my integrated sound and SB X-fi on the other hands does not work together (even one at the time without driver re install)