However if you use speed RAM modules higher than 1600 mhz I advise you to upgrade the bios before changing any value. For my part, with G.Skill Sniper 16GB strips (2 x 8 GB) DDR3 1866 MHz CL9, I first change the values in the bios, but I got the blue screen to launch windows. In short, discount defaults and updated the bios later, I was finally able to take advantage of the 1866MHz modules (after changes in the bios).