on newegg, there are some hd7850's at $170 (http://www.newegg.com/Product/Product.aspx?Item=N82E16814161426) and some at $235 (http://www.newegg.com/Product/Product.aspx?Item=N82E16814121650) whats the difference? only dif i see is the core clock, and they would be easy enough to oc at home anyway. i know that the ASUS one has some software for OC in windows, do the cheaper cards have that? thanks