tbh is there a great deal of gain in overclocking one of these? i tried mine and i could go up, but it never really made any difference to what settings i could use in games or anything else, it just gave higher benchmarks. running them at stock now to be safe. but as suggested, if your not confident go up in small steps, start with the CCC as this will generally be within the 'safe' boundaries, if thats not enough for you then, you can give afterburner a go. start with getting the core to its most stable, then work on the ram.