@shahroze042 if you are lucky u can go much higher or even not tuch your clock :) but stress it for like 30 mins to 1 hour to see if it not fail.... the one i'ev tested overcloacking reach only 600 core clock, 450 mem clock and 1405 shader, stabile with aftermarket cooler, it failed on 650 mhz co...
The corsair h 70 shows better cooling performance... even the h50 can beat this .. :/