Should be XMP set Profile 1, then you will see the ram frequency will run up to 4000Mhz !!!
P.S. I use Gigabyte Aorus Pro Wi-Fi with G. Skill DDR4-3600 CL17 4 x 8GB, just set ram to XMP Profile 1, it's running stable at 3600Mhz CL17...fine tune is not necessary!