It looks like NVIDIA’s reference design for both the 9600GT and the big daddy dual GPU 9800GX2 include S/PDIF passthrough. If you take a look at the pictures of the cards at newegg just about all of them include an internal S/PDIF passthrough cable and either have an HDMI adapter or include HDMI directly on the card.
I assume this is to compete with ATI having native HDMI audio. Since ATI’s native HDMI audio is a let down and pretty much S/PDIF over HDMI anyway, this means that ATI and NVIDIA are pretty equivallent, and NVIDIA may even have a leg up because you can hook their cards into anything that has a S/PDIF header, so if your on board sound had Dolby Digital Live or DTS Connect you could benefit from it over HDMI, ATI’s solution can’t.
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