Manicdan: yes, right, my example lower:
profile 1: 1.35V (undrevolted) 3718Mhz/2620Mhz
profile2: 1.375V (undervolted) 3825Mhz/2550 MHz
profile3: 1.44V 3950MHz 28xx NB
profile4: 1.5V 4010MHz 28xxNB
max stability 1.536V 4032MHz

As i see, efectivity going up profile 3, others MHz are not good for increase voltage (for 60 MHz i need +0.16V)