Masquerade20

so...i have one of these motherboards... mine says it's ALLOYSEED x79t but ont the bios it says "to be filled by oem"....but anywas...thing is....i have an 8 gb ddr3 1866mhz installed..but no matter what i do the ram still running at 1333 mhz... my bios version is 4.6.5 UEFI bios project 0.20...and it's on that retro AMI bios... the version seems to be 2012... I'm telling this things so i can be very specific to the issue I'm having...and since linus had the same i don't know if someone could help me on this mission.... i can only chose the speed by an option that says "force speed (.....)" (.....) this coud be from 800 to 1866 so if anyone could help me... please...i dig it too much on google and found nothing and have no idea where to go now....