i have an nvidia gtx 670 that i use and have hooked up to my sony surround sound system through hdmi, then the sony reciever connects to my tv via another hdmi cable. i get audio then from the gtx 670? and i have a creative x-fi titanium pci-e x1 sound card that i have been thinking about using, and connecting it to my reciever via toslink opticle cable, but i dont know if it would be better than the audio from the hdmi? if someone could let me know, that would be great.