Which is the better card? The 7900gs can overclock while this X1900gt appears to be a newer, lower end version of the X1900gt that cannot OC to well based on the reviews.
7900GS
http://www.newegg.com/Product/Product.asp?Item=N82E16814150208
X1900GT
http://www.newegg.com/Product/Product.asp?Item=N82E16814102022
7900GS
http://www.newegg.com/Product/Product.asp?Item=N82E16814150208
X1900GT
http://www.newegg.com/Product/Product.asp?Item=N82E16814102022