Using my MSI Z170 PRO motherboard bios I cannot get my 6600k to go past 39 clock ratio. I do not experience any crashing and everything works fine at 3.9 ghz (which is better than the original core clock speed of 3.5 so i can overclock some) but the bios will not allow my to increase my clock further. I have XMP for my RAM enabled and all my voltages are auto. any help?