As in the title, I bought an ASRock Extreme4 X99 (90MXGVL0-A0UAYZ) and Corsair Vengeance LPX 16GB (4 x 4GB) DDR4-2666 (CMK16GX4M4A2666C16). I though I was completly fine till I opened motherboard box and started reading manual (to be prepared how to set everything up when the rest of the parts arrive) and what immediately caught my atention was that in the specification about the memory pins it said "2 x 284-pin DDR4 DIMM Slots". My memory that I got is 288-pin but the guy that helped me setting this build (I considered him good with this, sience he set up his own 2 builds alone) said that everything was fine and pc-partpicker didnt find any problems, even the ASRock website had a list of compatible memorys and this one was there... So I am stuck and dont know if I bhough some kind of wierd version of X99 :/ the only hope I got is that someone told me that 288 pins work togheter with 284, which actually is hard for me to belive, thats why I would like confirmation if it will work or should I give the motherboard back?