The only (2) voltages for the RAM that you want to adjust are the DRAM Bus Voltage & QPI/DRAM Voltage but only if needed.
Example RAM Rated voltage = 1.6v
DRAM Bus Voltage = 1.6~1.65v
QPI/DRAM Voltage = 1.25~1.3v
Also, if your RAM is XMP then you can try AI OC Tuner -> XMP, failure use Auto and set the DRAM Frequency, CAS Settings, and Timing Mode.
Q - What exact XMS set, I prefer a link, are you using?