Is your Yamaha new enough to have ARC (Audio Return Channel)? I do a lot of gaming and to get rid of any lag I plug my PS3 and Xbox directly into the TV. With my setup, a Samsung PN60E550 and Onkyo 708, I have to plug the receiver into HDMI2 on the TV and have the game in HDMI3 (although the game doesn't matter which channel it uses). Then I had to turn "HDMI Control" on in the receiver (don't know what Yamaha calls this exactly) and viola! ARC!. This passes full surround to the receiver which Optical doesn't always do because of the copy protection garbage. The only downside, if you can call it that, is that ARC won't necessarily pass through every single type of codec out there. I haven't been able to find a list yet of which ones are down-converted to something else?