do i strictly need a heatsink like cooler master hyper 212 evo for overclocking core i5 4690k

[Sibasis Biswas]

do i strictly need a heatsink like cooler master hyper 212 evo for overclocking core i5 4690k?

 

[drixkarasu]

The stock cooler might be able to handle a light overclock, but the temps will probably be quite high.
Higher temps can reduce stability and will shorten your CPU's lifespan.
So no, you don't strictly need an aftermarket cooler but it is highly recommended.

 

[smorizio]

with a cpu cooler you look at it ratting is wattage that it can cool. with air coolers to get higher watatge cooling there going to be large and heavy. the smaller sealed water coolers are smaller. mysefl i like the larger air coolers. if the fan fails the cooler still going to work. the water units if the pump fails...your rig is down till the new unit comes in.