Troubles with Sabertooth Z77 and ASUS Xonar DGX

Hey there guys. I am having some difficulty with my Sabertooth Z77 motherboard and my Xonar DGX sound card. It seems that I cannot have Windows recognize both my sound card and my onboard audio at the same time. I have to go into my BIOs and disable the "HD Audio" for the sound card to be recognized. Is there a way to have it recognize both at the same time?

I doubt it, have never tried running both at once myself.

Why would ya need to, out of curiousity ?

I'd imagine that would cause a lot of conflicts, why there is the ability to disable the onboard sound to use a card.

The reason why is because I wanted to have my headphones and speakers plugged in simultaneously. The headphones use one of the same plugs as my speakers do.