I just updated to the beta drivers released yesterday, and yeah video playback is not fluid when outputted to my 1920x1200 resolution display. It is very choppy and not enjoyable.
I suspect that the displays used in the demonstrations were 720p displays...
At any rate, it seems upscaling in general will cause it to slow down alot. My CPU usage is still low, so I'm confused as to why it does this. I'm hoping its a software problem that will be corrected when the final release rears it's head.
N10J-A1 :: @1.95 GHz :: Windows 7 Professional // Windows XP Professional (TinyXP)
Main Rig :: Asus P5B Deluxe :: Intel C2D E6400 @ 3.0 GHz :: GeForce GTX 275 :: 6GB RAM :: Windows 7 Professional 64-bit // Windows XP Professional 64-bit