It will run @ the stock speed 3.4GHz (3.8GHz TurboBoost).
The K model you're paying a bit extra for has the un-lock CPU multiplier that makes OC'ing easier.
The CM Hyper 212 Evo will help keep it cooler if/when you OC the CPU.
@ the OP. You have a psu meant to run two of those cards, yet a board that only runs a single card. Either you have the wrong psu, or the wrong board up there. Also you don't need to purchase any thermal compound like that Arctic Silver seeing how CM cpu coolers come with a small tube of MX-4 which is about as good as it gets in regards to thermal paste.
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