I use offset voltage to overclock my chip.
Say you want, in your case, 1.290v. You can set this manually or you can change the bios to use an offset. So, for example.
If at 4.5GHz the mobo will automatically pump 1.370 volts and you only want 1.29, use an offset that will bring you down to 1.290 (or what ever it is before drop),
Normal 1.370 minus offset - 0.080 (i'd expect you'd need -0.050 to get 1.290 because of vdrop).
Hope that helps.
Edit:
Look at my sig, my chip requires 1.33 load with llc1. The mobo will auto volt to 1.370 so I have a offest of -0.040 set,