The graphics CARD on my computer has an DVI-I dual link port out.Just purchased a new monitor that has an DVI-D port in and also came with the DVI-D single link cable.The cable will plug into the graphics card but does not have as many pins.For now I am using the analog cable between the monitor and graphics card but WOULD like to use the digital cable if it is compatable.http://www.anandtech.com/video/showdoc.aspx?i=1577&p=3
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the DVI-D connector features only the 24-pins necessary for purely digital operation while a DVI-I connector features both the 24 digital pins and the 5 analog pins

DVI-I is a connector that is compatible with both DVI-A (analog) and DVI-D (digital), which are not compatible. DVI-A is largely a computer format. DVI-D is the consumer variety of DVI, the one that most people consider to be the same as HDMI without the audio (slightly inaccurately); it has found its way into the computer world between certain video CARDS and displays. DVI w/HDCP is DVI-D that carries the digital copy protection that is found most commonly on HDMI; at the DAWN of DVI on consumer-video products, HDCP wasn't always included, sometimes making it incompatible with subsequent products that demanded it. DVI, component, and HDMI are all capable of resolutions higher than 720p.