I know this has been asked and answered before but just wanting reassuring. Currently ddr4 2133mhz is same price as ddr4 2400 . I have i5 6500 and gigabyte z170 gaming 7 on its way. Any reason to purchase 2133 over 2400 or vice versa? 2400 will run 2133 if not over clocking right? Thank you so much