QVL lists usually state the following, regarding high speed memory modules "The stability and compatibility of these memory modules depend on the CPU’s capabilities'' that means such ram is best suited for unlocked i5/i7 and not for low or mid range cpu. also by experience , i havent seen any of the locked i5 go beyond 1866mhz . i have built non k i7 running 2133mhz but not i5.!