Roxas_Boy :
Because you want more performance duh
The manufacturer tested it to that speed with no errors detected at any level which are too numerous to mention here. The speed stamped on the processor is what it should be run at not duh it works at this speed too. Do you own the equipment to proof the speed is without errors and every bit is accounted for? If not don't post you can overclock, everyone is just fooling around.
Want to go faster, buy the faster processor.