to simplify my setup im wanting to replace my media centres 8600gt with a hdmi card with audio. What i cant seem to work out is if the combined cards like the Sapphire HD 4670 Ultimate Edition actually have their own sound card or they pull the sound in some way from my existing sound card (soundblaster z-fi extreme) And if they dont i take it the only audio output i will have is hdmi so if i want to use headphones they have to go in the amp?

i assume if the combined card has its own sound card rather than using another it will still get audio from other programs and not just act as a pass through from dvd/blueray disks like a normal sound card

sorry if this looks daft i just keep getting contradictory information when i do searches some sources refer to it as a hdmi passthrough some as a sound card