Originally Posted by
AOD_Mokona512
The K series are unlocked so you can overclock them (always go with a K series unless you are going to build a really low powered system for use as a NAS or something)
The 4790k is the same exact chip as the 4770k but it has a slight factory overclock and a better heat spreader so it should allow you to get better cooling without having the delid the CPU and replace the thermal compound under the heat spreader. (voids the warranty)
If you have the money, go with the 4790K, you will be able to get better overclocks without having to delid the CPU.