I'm getting a little out of my league with this new setup. I've been wanting to try out 5.1 on my gaming setup. So I picked up an open box Pioneer VSX-522 receiver, I have it connected via HDMI from my 6970. That part was simple. 5.1 content plays back great, all channels are working properly. The problem is upmixing, the receiver doesn't have the ability to enable Dolby Pro-logic II or anything else based on the input I'm using (HDMI). I was under the impression that using the HDMI connection is superior to Optical because optical won't pass anything but compressed PCM. This receiver doesn't have 5.1 analog inputs. I'm sure that the computers onboard sound can upmix but it's not being used because of the HDMI output of the video card. I'm guessing that an external sound card with HDMI can process/upmix 2 channel content before its sent out, but I don't think that I want to buy a 150$ sound card that will only be used for its ability to upmix. I think the real question is this a limitation of my receiver? Do other models have this ablity? Other brands don't specify if they can do this kind of processing or not. The sales people I spoke with didn't have a clue about my configuration. I'd be willing to return this receiver and get a different model but if it's just going to cost a bunch more money, I'll just live with it.