Just so you know...
EVERY overclock is different. Even two CPU's of the exact same model will overclock differently. This is what nukemaster was referring to when he said you need a "damn good chip" to hit 5GHz. You get CPU's that overclock well and others not so well - its just luck of the draw.
There are also countless other factors such as motherboard, case, ambient room temperature. The list goes on....
So if you see someone getting 5GHz with a certain setup this doesn't guarantee you will achieve 5GHz even with the exact same setup. You might get more, you might get less, it's all about tinkering around until you find the stable limit for your particular chip.