Each cpu is different, from different batches. Some websites post their overclocking results so you can see if your batch has a better chance of a high overclock. I don't raise the cpu voltage when I overclock, but if you change the cpu/board often, then you may not care how long the system runs stable with the overclock and voltage increase. Overclocking and raising the voltage stresses the cpu and board components somewhat; can't guarantee if your system will run stable until it croaks. But it's fun.