Here is the hardware:
ASUS P5NE SLI with 3.15GHz proc, 8GB memory, 64GB SSD boot drive
Auzentech Explosion 7.1 PCI sound card
Galaxy GeForce GT 440 with VGA, DVI and HDMI output (no audio headers on card)
Yamaha RX-A800 Receiver
Samsung 40" LCD Display
Viewsonic Pro 8200HD Projector
When running Windows XP Pro, using the Explosion's coax digital output and HDMI to the receiver, XBMC plays perfectly.
Attempted an upgrade to Windows 7 Pro 64-Bit. All drivers loaded fine. I am unable to get audio over the HDMI cable. After searching the net, it would seem the video card is capable of doing it. Here are the steps I took:
Remove the Explosion card. Enable onboard audio in Bios. Load the latest GeForce drivers for my card which includes the HD Audio driver. When running the NVidia control panel, I can clearly select HDMI under audio and I see one of two sources, depending on what destination I use, either Viewsonic 8200HD or Yamaha A800. I open the sound control panel and HD Digitial Audio is the default option, others include headphones and speakers. At this point, sound is just not transmitted to the receiver when running sound tests. I can clearly see the sound bar showing the rise and fall of sound during the test.
I connected the coax digital output to the mainboard output and to the receiver. Sound works but dropouts are so significant that it's unusable.
I disable the onboard audio and install the Explosion card. I connect the coax to the Explosion and sound works a little better but audio dropouts are still appearing about every 5-10 seconds, once again unusable.
The hardware should be more than enough to play the most intensive 1080p mkv files, and in fact under Windows XP, they all play and sound fine.
What am i not doing here to make this work? Can anyone confirm that the Galaxy GT440 with the yellow fan will carry HD audio over the HDMI port? Is there a setting somewhere that I'm missing?
Should I just throw in the towel and install Windows XP 64-Bit and call it a day?