What cooler is good for overclocking i5 6600K to 4.5GHz?

[IMichI]

im looking for air cooler.

 

[Dark Lord of Tech]

Case ?

 

[Acapella]

That's a high goal. It really depends on the chip you get. Better cooler won't linearly increase performance. All chips are different. I've always used the Hyper 212 EVO, but it's definitely not a top-end cooler. I don't know that it's worth it to splurge on a cooler aiming at a goal that might just be physically out of reach for your chip. But I'd recommend you look here: http://www.tomshardware.com/reviews/best-cpu-coolers,4181.html