i used some online power supply calculator and it claims it should have enough power but i want to double check before i buy it also is what is the difference between these 2 cards besides $5
http://www.newegg.com/Product/Product.aspx?Item=N82E16814127761&cm_re=r9_270x-_-14-127-761-_-Product
http://www.newegg.com/Product/Product.aspx?Item=N82E16814127794&cm_re=r9_270x-_-14-127-794-_-Product
http://www.newegg.com/Product/Product.aspx?Item=N82E16814127761&cm_re=r9_270x-_-14-127-761-_-Product
http://www.newegg.com/Product/Product.aspx?Item=N82E16814127794&cm_re=r9_270x-_-14-127-794-_-Product