hello i have an older card its an amd radeon HD 5750 1gb and when i enable overdrive at clock 870 MHz memory 1420 MHz and i se tearing and flickering all i want is a bit more out of the card how do i fix this and be able to enable overdrive? just ask if anymore cpecs are needed and this is the exact card i have http://www.newegg.com/Product/Product.aspx?Item=N82E16814102865