Use MSI After Burner which is the best software for GPU Overclocking and OC your GPU... Every GPU Clock from others may vary from yours or your GPU... Manual OC Settings is recommended because sometime you can reach higher than other people... For example, there's this guy have a Evga GTs 450 and OC to 905MHz Core Clock awhile mine Evga GTs 450 OC to 900MHz Core Clock which is a 5MHz different and when i try 905MHz, the driver stopped... You have to OC and test it yourself to find it... First try a big step forward like add 150MHz Core Clock and test if stable... Also try 200MHz Memory Clock and see if stable.. Use furmark or play a game(Dont play low end game, play something like A.V.A. which is from steam-Free To Play) which is better than furmark testing...