So what i do is get a gpu stress testing program. So first start bumping up all the parameters by 10: the memory clock speed, core clock speed, and core voltage. after you have done that run the stress test for about 2-5 min if you see everything is stable and you see no artifacts then repeat the process until you hit the max. for OC software i would use MSI After Burner (scroll to the bottom for download) and for the stress test i would use MSI Kombustor