AMD 785G Update - Multi-Channel LPCM is not Available
 

Let’s just rip the Band-Aid off quickly here. We have touted, as have many others, that the 785G chipset provides multi-channel LPCM audio output. We went over it in our press briefings from AMD and in previous conversations with them and others. It turns out that in retail boards and with the current 9.8 (8.634a) driver set that an audio block exists which limits LPCM output to two-channels. In other words, the 785G is no different from the 780G/790GX chipsets in this regard.

As of now, our initial preview coverage and review is incorrect regarding this feature set. For most users, this will not matter, as two-channel LPCM is available along with 5.1 S/PDIF audio outputs through the HDMI port. However, for the serious HTPC crowd, the lack of multi-channel LPCM is a huge drawback when selecting a platform that will be the centerpiece of your media center. The Intel G41/G43/G45 and NVIDIA GF8200/9300 series of chipsets fully support multi-channel LPCM output as does AMD’s own HD 4xxx series of video cards.

http://www.anandtech.com/weblog/showpost.aspx?i=629