So i bought new rams for my pc ( hyper X fury up to 1866 1.5 v ) put them in my computer and started , i entered the bios and changed them to 1600 with cas 10-11-10-30 ( altho i read after that @1600 the cas can be lower) so everything was fine . the next day i try to put 1866 , and boot loop started . did everything : CMOS clear , remove battery etc . Untill i switched back with my old memory ( 1 STICK ONLY ) and the system booted . Now the new RAMS are good, but probably my system doesn t like 1866 , IS THERE a way to somehow " reset " the new ram to 1600 ? like trick the BIOS ? my MB is a z68X ud4 , it s compatible with the new ram i bought ( fro m kingston website)