It depends upon what frequency you're running, if for example you're running them at 1600 MHz then YES use 1.65v. However, 'SPD' e.g. 1066, 1333, etc then use 1.50v. Those are XMP so you can select AI OC Tuner or XMP Profile -> XMP. If you OC your CPU then I recommend setting ALL parameters manually {DRAM Frequency/Multiplier, CAS Timings, and DRAM Voltage}.