I used to use a usb headset before I got a dedicated sound card. When I switched to the sound card and disabled the onboard card and got rid of the usb headset I not got improvement in the game sounds, but also better frame rates. It made a noticeable difference immediatley. I'd hook it up using the standard jacks if you have that option available to you, especially since you've already got a dedicated sound card going. I'm no computer hardware pro, but that's my .02 based on my experience.