This will simply overclock your CPU when it passes a certain point, giving it only an overclock when needed. It is basically an overclocked turbo mode. Please not that this will disable cores, which may not be preferred if you are not looking for single or dual core performance. I prefer to disable turbo mode, and just increase the regular multiplier.
The multiplier option can be found in the BIOS. Some motherboards do not have this feature, so if you do not find it please post your motherboard model.