I thought the Nvidia cards had an audio processing chip on the cards as well and the SPDIF cable only transferred the input to the card. I didn't realize the audio had to be processed by your audio system, then transferred to the Nvidia card to be trasmitted over the HDMI cable.
P.S. You can still use a DVI to HDMI cable with an ATI or Nvidia card, but you will need the audio to be connected in another way.
The only difference is that ATI Cards have onboard HD audio processors, but nVidia needs you to use one on your mobo or audio card. The nVidia card only connects the audio from you sound card to the HDMI cable and adds the video to it.
I didn't think ATi cards required special converters. I thought all the HDMI to DVI converters dealt with the sound in the same way, since nVidia also transmits sound through the DVI connector. In fact I think I'm using an ATi converter with my GTX285 right now...
Not sure about the DVI to HDMI cables, I'll have to check that when I get home...
No, it's not a DVI "converter", it doesn't convert anything. It just changes what sort of cable you can plug into the port. The DVI port will be getting supplied with audio already, but the DVI port on the monitor/TV doesn't look for an audio wave because the standard is not designed to (correct me if I'm wrong).
To recap, ATI cards have audio processors, so they just send audio to the DVI port, and nVidia cards don't, so they route the audio from the mobo/sound card to their DVI port. The HDMI adapter is just like changing the head of a screw from flat so star, so that you can use a star screwdriver, similarly it changes, the shape of the port from DVI to HDMI so that you can use a HDMI cable instead. The HDMI port on the monitor/TV will look for audio, that's why you want to use the HDMI cable if you want audio (correct me if I'm wrong).
That make sense? Here are the plugs:
DVI PORT (on graphic card)
DVI Cable pins
HDMI Adapter pins
As you can see, the DVI cable is single link, which is in pins 1, 2, 9, 10, 17 & 18.
The DVI-HDMI adapter supports a dual link, the pins above for link 1, and the pins 4, 5, 12, 13, 20 & 21; carry link 2.
If I'm not mistaken, it's the 2nd link pins that carry the audio wave, thus you can see that DVI physically doesn't support audio (again, I might be wrong in the audio on link 2 thing).
I hope this helps (just ask if you don't understand, and please correct me if I understand something wront).
Sorry if this is a topic infringement.
