Hi, I have a GIGABYTE GA-EX58-UD3R overclocked to 3.2 (3.4 when x21) no problems when I use 3x2GB Dimms (OCZ 6GB DDR3 PC3-10666C9 Gold) But Today I bought another set of 3x2GB (Same Model same Brand) to use 4 Dimms (My Mobo have only 4 Slots) but my overclock doesn't start anymore. What is happening? I'm also mix one of the New Dimms with the old one and use 3x2GB with no problems so aparently the problems is only when I use the 4 Slots. any suggestion is more than welcome. BTW I Manually add Timing in Bios.