As I understand the graphics card sound make no difference. It just takes a SPDIF output from your soundcard (in your case it sounds like onboard sound) and combines this with it's video output. I believe you just need a soundcard (and drivers) which support bitperfect playback.Question. Is the same possible with an ATI 3xxx graphics card which is able to output HDMI video PLUS audio over an DVI>HDMI dongle?
At the moment I sometimes have proper sound (5.1). I use this DVI>HDMI dongle from ATI in combination with my HD3450. Basically it adds a SPDIF stream to the DVI output. There is a little connector between the mainboard and the ATI card. What do you think. Possible?