Geforce 260 unknown wire usage

[bruzed]

I recently got a EVGA Geforce 260 and I am absolutely clueless as what this S/PDIF connector does or where I plug it in on my motherboard, is it important and if it is why. I also have a minor question in reguard to whats the difference between 8xMSAA and 16xMSAA settings when in counter strike and why i may be getting a tearing like distortion in the middle of my screen when i play Crysis.

 

[spathotan]

The cable is worthless.