Gigabyte 4650 AGP problem: (no Dolby 5.1 option using HDMI port). The card is installed and works great but I only get 2 channel Stereo from my HDMI port..(Control panel, Sound, Playback Tab)...is this all the card offers or is something wrong...?? Windows 7 64bit
Yeah, the HD 4670 does not have that capability. You would need a Radeon HD 5xxx or 6xxx series card for that particular feature.
However, there are no AGP versions of those cards. Therefore, if Dolby 5.1 is really important to you, then you will need a new computer that has a PCI-e x16 graphics slot which is pretty much standard nowadays.