Audio over HDMI from SPDIF-Out on MB?

Hi All-

I'm in the process of figuring out if I'm able to do the following. I'm in the exploratory stages of building a diskless (PXE Boot) xbmc HTPC boxes with VDPAU patches and the MythBox plug-in. All of these boxes will be running Ubuntu 8.10 x86_64 (Linux).

I am "recouping/reassigning" hardware (MB/CPU/Memory) from four of my eight LAN gaming machines which were built from previous Fry's CPU/MB combo deals over the years. The four motherboards being used will be some iteration of an ECS Motherboard which I have verified having SPDIF-out 4-pin headers on the motherboard from the on-board Realtek or similar integrated soundcard. These four HTPC's would be replacing four Popcorn Hour A-110's in the house.

So this leaves me finding a replacement video-card for this build which has native HDMI on the board itself which accepts SPDIF input and will give me audio over HDMI (PCM, DD, or DTS) that works under Linux/xbmc.

I've seen many nVidia 94xx/95xx PCIe cards which have native HDMI ports and an SPDIF in header on the videocard. But I know all I really need are 84xx/85xx class cards for VDPAU. So my questions are:

1. Are there any 84xx/85xx class nVidia cards with native HDMI which supports HDMI audio from an SPDIF header?

2. Are there any 94xx/95xx class nVidia cards with native HDMI which supports HDMI audio

without an SPDIF header? (I've only seen IGP versions support HDMI audio without some type of SPDIF jumper).

3. Which are the quietest iterations of any of the cards that people are recommending for HTPC's which support VDPAU? Either fan or fanless solutions.

4. Without going to an IGP solution (i.e. new motherboard), is there any way to get multi-channel LPCM (i.e. 8-channel LPCM) working over HDMI on any of the nVidia cards in a PCIe interface? Most of the content for playback on the xbmc machines will be 1080P archive videos and 1080i/720p HD channels from either OTA or Clear QAM from my local provider (mythtv backend will be running under a Xen VM using HDHomeRun's for tuners).

These four xbmc HTPC's would be fed via HDMI (A/V) into Yamaha RX-Vx65 receivers which support HDMI audio and then pumped to 1080P-class displays with HDMI.

Any help, comments, suggestions, welcomed. Thanks in advance!

Thanks, everyone, for the replies!


That's definitely an option. I'd just want to see if I can just do it with a single cable. But you're right; I could just make a cheap SPDIF bracket for the header on the motherboard and connect it to the receiver. I was just hoping not to lose one of the precious optical & coax digital inputs on the receiver.


Yup! I just missed out on Newegg's Deal of the Day today. They had the Sparkle 9400GT 1GB fanless PCIe for $34.99 shipped. That would of been perfect!


I have some VC-1 encoded content (mainly the IMAX stuff I've ripped from Blu-Ray's). I'll just keep my eye out for G98-based fanless video cards.


Good question! I'm trying to make the front-end machines as quiet as possible without generating a bunch of heat. Any HTPC, sans the upcoming nVidia ION platform, is going to be larger, heavier, louder than a Popcorn Hour. That's why in the process I wanted to be able to use HDMI connections only between each component so to keep one less cable to string if I decide to hide the components in a ventilated area away from the display device and seating area and run an IR extender/repeater.


I have an MSI Wind PC (Atom N270-based one; First Gen) which is a basic Windows XP workstation. It's extremely quiet and doesn't output much heat at all. Just the lack of even a PCI-slot kills it for an HTPC. Atom N270 is plenty of power when VDPAU is in play. I have an ASUS N10J-A1 corporate netbook I use which has an nVidia Geforce 9300M GS chipset with HDMI out and playing nominal Blu-Ray 1080P bitrate video with LPCM coming out of the HDMI port just fine. No stutter at all.


This is exactly how I understand it too. It's just SPDIF "pass-through". Which means no DolbyHD, no DTS-HD MA, no LPCM 8-channel (but PCM Stereo is fine). This is the "loss" I get from not going with an IGP solution but with boards running around $120 (for Intel CPU, Geforce 9xxx IGP;s), (*4) versus $35 (*4), saving about $320 USD and not having the above capabilities... $320 is a nice chunk of change.

Thanks, again, everyone for your help! Just an update for where I'm at now, I have an MSI dual-slot 9600GT (which just happens to have the SPDIF-in) which passes through the SDPIF to the first DVI port on the card. It came with a DVI-to-HDMI adapter so I'm going to use this box as a test box to install Ubuntu 8.10 to an iSCSI target on my 6TB RAID server via GbE to make it diskless. Wish me luck!

Cheers,
Kermee... who likes to over-engineer things.