Differences between CM 212x and 212 Evo

[Huntsman86]

i dont know anything about cooler, can someone tell me whats the difference between CM's 212x and 212 Evo and which one should i get, or should i get a different cooler?
my build http://pcpartpicker.com/p/KGDDvK

 

[utgotye]

Truthfully, you likely won't need anything other than the stock cooler. That said, the EVO lowered my 4790K's stock temps 10 - 12C minimum vs the stock cooler.