I'm building my first PC, and I bought an ASRock X99 Extreme4 Motherboard with a Raidmax Viper GX case. Both case fan cables are long enough to plug into the smaller thin prong headers, but then there's only 1 12V header with 4 large prongs that the other end of the case fans are supposed to connect to(?) I'm really lost and not sure what to do next, please help me out!