I'm having an issue overclocking on my Asus Maximus VI Hero. I've set AI Overclock Tuner to xmp, cpu core ration to sync all cores, and change it to 42. It shows within BIOS the 42 and the target speed to be 4200. After saving and checking CPU-Z and AIDA64, both state it's still at stock 3.5. I feel like I'm missing something very simple here. What am I doing wrong?