The ram timings and voltage seems to be funky with DDR3 especially 1333 mhz which needs precise manufacturer voltages and timings to run stable. It seems the mainboard manufacturers energy savings "cool and quiet ect." which enables processors and graphics and other hardware to reduce voltage when not needed. This seems to be why these ram voltages need to be set manually as they are set to auto which reduces the voltages in sleep mode or in light use,either way voltage fluctuation or lack of voltage to the ram is the cause of the instability. Most manucturers list ram timings on the ram as well as voltage. The Bios is another story, don't attempt any voltage changes without proper knowledge of Bios and mainboard installation.Set ram timings and voltage test with memtest.Check timings in CPUZ.
Peace out.