I am not sure how to overclock the Core clocks. I have increased the memory clocks from 1500mhz to 1700mhz. its stable while playing Sleeping Dogs maxed out. But as soon as I overclock the Core clock to 1100mhz, the video card resets itself and i get black screen and the game crashes. I also tried to increase the powerlimit and voltage to +25 offset but still the video card does the same thing. Right now its pretty stable at default Voltage and Powerlimit when the Core clock is at 1067mhz and memory at 1700mhz. What would be the right powerlimit and Voltage to make it stable at or above 1100mhz Core??? my card is MSI GTX 670 2GB.