You want to focus on P6 and P7 (this is your core clock and core voltage) and then P3 (memory clock and voltage). You need to make P6 voltage slightly higher then P7. You can carry the P6 voltage all the way back to P2 for the core. I don't adjust the memory voltage only the memory clock in the middle of the program under p3 (p1 to p3 columns). I believe it helps maintain stability and you'd only save a couple watts at most by undervolting the memory voltage. Most of your savings will be the core clock and core voltage in p6 and p7 on the left side of the tool. Since the gpu runs 100% almost all of the time for utilization the most relevant field is p7 core clock and p7 voltage.