i OCed my gpu , 650 to 762 right now for core, when i push it to 775, i get tiny black lines on the screen sometimes. but i havent changed any voltages yet. if it increase the voltage, will i be able to OC it more?
You can't change the voltage on the gpu and those black lines are probably artifacts. You can download ATItool (if you don't already have it) and run a scan for artifacts. Also 650 to 775 is a 125 Mhz OC and that's good but its probably too high if you have artifacts. Oh and bad news artifacts never go away thats why you should always be careful when you over clock. Hope that helps.