The following discussion is based on the premise that it is the video/movie optimized sound card you are looking for. One of the most talked about cards in this category is the ASUS Sonar HDAV 1.3 Deluxe. 
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It is a PCI Express card and takes the space of two slots. The card has a HDMI 1.3 compatible output. The HDMI 1.3 output can be routed through the HDMI output of the video card, that is a special feature of this card. There is no need to down-sample the Blu-ray disc sound input. You can enjoy Dolby True HD and DTS Master audio because both are supported. The card works with ArcSoft TotalMedia Theatre software and it supports all three Blu-ray disc video formats as well as other video formats such as WMV, Quicktime and H.264 HD etc. The software supports the HDCP digital rights management system too. So that there will not be any problems with protected content play back. The product separates out analog and digital signal grounding and shielding that is essential in creating a clean audio sound. Look at the image gallery picture, where the shields show clearly. The audio quality is also helped by the use of high quality oversampling digital to analog converters and other components in audio processing that help create high SNR (signal to noise ratio) audio. Use of the special software to operate this card might look like a bother to some. The card costs around $220 to $230.