for 1 it is a noobish question however the only way u can up the GHZ in ur computer is by overclocking and u can tell by programs like CPU-Z and stuff like that.
You can also tell him to stop lieing cause unless he has alot of money to waste and is useing liq. nitro. to cool his computer its almost impossible to get it up to 12ghz.
Heres a tip remeber GHZ isn't the best thing to look for. if you wanna know y i can explain that also.