I'll be watching on with interest for this thread as I agree, even the top of the line HTPC cases do not come with the 16 socket plug to suit HD Audio - just the 10 pin regular audio socket. My DG45ID HD Audio headers remain unused as a consequence. Most boards now come with a full range of sockets at the back but for someone who wants all of this audio connectivity at the front of the case, I'm not aware of an elegant solution.
This audio solution has great specifications on paper with multiple chanels on lots of streams which all sounds very good yet it does not seen to have ever been finished, adopted or even fully accepted. Apart from the issue of having had great difficulty in finding compatible hardware (I have found one socket manufacturer who seem to make a suitable product but I don't want 10,000 of them) I still cannot find anybody who makes anything at all in the way of suitable interfaces.
I found this on the Gateway site which seems to indicate that Intel themselves were supposed to make something but where is it?
"This is the HD audio link connector on the motherboard. This connector is a digitized serial interface used when an Intel® HD Audio controller is installed in one of the PCI Express slots. A cable is employed between the controller and this connector.
Intel HD Audio is the next-generation integrated audio solution for PCs. It provides up to 15 input and 15 output streams at one time and up to 16 channels per stream. It has a bandwidth of 48 Mbps per serial data out (SDO) and 24 Mbps per serial data in (SDI)."
It is all probably a bit academic now but I hate to think of the amount of work taken to develop this interface just to see it lost due to indifference. Having now read what is required of HD Audio for the front panel I realise that it was never possible to make an HD/AC'97 interface on the same hardware anyway.
"This is the HD audio link connector on the motherboard. This connector is a digitized serial interface used when an Intel® HD Audio controller is installed in one of the PCI Express slots.
Now you mention this, it does ring a bell but good luck finding one of those illusive cards to put into a slot and connect to the header pins! Intel needs to rename the 16 pin header to be called a HD Audio BUS connection as it's easy to forget this is meant for a proprietary card connection and NOT the front of a case (case in point is it happened to me here, even though I'd heard about this some time ago).