VDroop-Mod
As many of you already know, the DFI board has some quite high VCore fluctuations under load. That's why some smart guys figured out a VDroop-Mod for this board, to reduce those fluctuations.
This mod is rather delicate as you need to remove 3 SMD/SMT resistors on the board in a cramped area and replace them by SMD/SMT resistors of different values.
The resistors, marked in the pic, need to be removed and then you solder in one of the SMD/SMT 4.7K resistors in each of the marked locations.
I'd advise you to order more than just the three needed resistors, as you may need to try that mod more than once before you succeed. Sometimes one or two resistors get damaged (due to overheating or whatever), so be sure to have a replacement!
VDD-Mod
Datasheet of the chip:
http://www.national.com/ds/LM/LM158.pdf
Connect the middle pin of the 50K potentiometer to Pin #6 (Inverting Input B) of the LM358 chip. Then connect the potentiometer's outer contact to Pin #4 (Ground/GND).
The measuring point for VDD is located in the top right corner of the pic. It's the right leg of the VDD mosfet.