i was originally using stock ram speed with my CPU at 4.2ghz. recently changed it to 4.3ghz and trying to OC my ram to 2100mhz. but sadly it failed during POST. so i changed to stock ram speed with it at 4.3ghz remains. after awhile like a month later. it starts to BSOD so i changed it back to 4.2ghz which is my old Settings. the BSOD still persist.