so I have two sticks of 8gb 2666Mhz DDR4 memory on my Pc and I want to upgrade to 4 sticks, but the model that I have (Ballistix Sport PC4-21300) is no longer available in a retailer that is near me, so I was wondering if I can add 2 sticks of HyperX Fury 8GB 2666MHz DDR4 CL16 DIMM 1Rx8 Black...