Hello, i've been having this issue ever since i upgraded to coffee lake and bought new ram to go with the proc and MB, i've got G.Skill Trident Z RGB 16GB (2x8GB) DDR4 4133MHz 1.35V CL19 Dual Channel Kit, F4-4133C19D-16GTZR , 2 sticks of 8GB, placed on the correct slots for dual channel (1 and 3) and when i enable XMP my computer runs slower than it should in regular tasks considering my hardware and my graphics card (1080ti) is bottlenecked to 1500mhz clock speed (boosts to 1900 when xmp is disabled). While gaming frames are halfed using XMP as they are whitout, to be more exact in WOW where i would get 30 FPS with XMP enabled i get 60-70 whitout it enabled, wich is stupid considering its half the frequency. While XMP enabled in bios it displays the correct numbers (4133) and in CPU Z it shows 2066 so i guess XMP works but in practice it bottlenecks my PC somehow halfening (or even under half) the usual frames. Even in final fantasy XV, regardless of settings, be they ultra or garbage low i do not gain or lose FPS, i'm stuck between 27-35 FPS constantly with XMP enabled, with it disabled settings work properly and depending on what i disable or lower FPS increases. Help, what should i do?Should i ditch this high frequency and get a 3000mhz instead? ( i know it was overkill from the begining but the price wasnt alot different between them so i went for the higher MHZ one) Or what should i do to make it work properly...i'd prefer to make it work rather than send it back to change it... Also my motherboard bios version is F6 (tested with F5 before and still same thing)