Since the fan on my nVidia card was dying, I got my myself a new ATi 4550 card for my Media Center. It does more or less my old card can do except one thing which is crucial. Although most reviews on the Internet said the differences between the nVidia's Purevideo and the ATi's AVIVO are very little, and in many case ATi solution is recommend due to its passive cooling (silent) and HDMI inclusion, after having both cards, I can say the nVidia's PureVideo is a better option if SDTV is involved.
ATi and nVidia may both handles high definition video very well and can offload works from CPU, however, HD isn't everything! PureVideo has the advantage of deinterlacing SDTV video which ATi lacks. The lack of deinterlacing on ATi card makes live SDTV on my media center look horrible. The "comb" effect is so obvious. Interesting enough, there is a solution, and it is from nVidia. It seems that PureVideo can run on ATi card too. After putting PureVideo back to my computer, the deinterlacing problem solved.
