I bought two video cards, Asus HD6570 1G and Diamond HD6450 1G, for just watching blueray and some HD videos, not for gaming. I thought there is no difference between video cards if only for watching videos. I was wrong. The HD 6570 is much crystal clear in the quality of video compare to 6450. How come many people said that if you are only going to watch HD videos, then most video cards are the same? Would someone let me know how to choose a PC video card for just watching HD videos? Is there any video card spec. that represents the degree of crystal clear in the quality it can be displayed.