all gpu's are made differently so you wont get the same overclock as another person with the same card. youre going to have to use a program like msi after burner and put the core clock up by 10mhz then check for artifacts . keep doing it till you see artifacts then when youdo put it down by 15mhz and right down your setting .then put it to default. then do the same with the memory clock . once thats done put them both at the settings you wrote.