Radeon 5xxx cards have onboard sound and support 3 monitors at once (you would have to use adapters, naturally has 1 HDMI, 1 DisplayPort, and 2 DVI-D. You could get 2 cards and do crossfire for 4 monitors at once.
I dont think there is anything on the market that matches your description. The best thing I could come up with is getting two cards with either DVI+HDMI+DVI or DVI+HDMI+VGA outputs and using an adapter to gain the extra two HDMI from DVI.
You can do multiple HDMI but you lose audio, since it will only provide audio through one output.
Also you cannot drive 3 HDMi via the DVI+HDMI+DVI of a card like the HD5870 etc because you only have 2 sets of TMDS and thus only one DVI will work if the other is powering the HDMI.
For single card you need either a dual GPU card that supports quad DVI out, and then doing the DVi-> HDMI conversion, or else getting the HD5870 Trillian 6 Display port output and then using active converters for HDMI.
Now the most cost effective way is to have 2 separate cards like the HD5450 if you're not gaming or else equivalents depending on power needed 5670 or more for more power. However do NOT crossfire them it complicates the monitor support, just hook them up to the 4 outputs/inputs.
But once again you are stuck with just a single audio output.
February 24, 2010 9:31:44 PM
This configuration is used to allow PC content to be shown simultaneously on 4 HDTV's that have been extended into 4 offices; allowing users to choose the 2nd HDMI input to view the common source. Once I determined exactly what functionality was needed, I put a Gen 2X4 switch in place and I'm swapping the Radeon 2450 for a active dual HDMI card.