well, if you just run your processor in stock clock, your cooler is decent..
but actually, no matter how good is stock cooler, it won't be enough for overclocking..
so, if you wanna push your processor to the higher clock, you should buy a aftermarket cooling..
coolermaster 212+/evo is the best price performance cooler.
it'll handle your processor heat at 4.2-4.4Ghz flawlessly..