If you look around at the reviews for Zediva most people comment that the quality is not very good. I don't think it's the CPU, as the decoding should be done by the video card, and that Ion 2 chipset can do full screen, H.264, 1080p without a problem.

Pioneer PDP-5020FD, Marantz SR6011
Axiom M5HP, VP160HP, QS8
Sony PS4, surround backs
-Chris