Sitting on a Rampage Extreme and a E8600. The board has CPU GTL Ref 0,1,2,3

VVT = 1.20

So i calcute this

1.20 x 0.635 = 0,762
1.20 x 0.667 = 0,800

0,762 - 0,800 = 0,038

= ~ -40mV

I´m i on the right track ?

CPU GTL Ref 0 = Auto
CPU GTL Ref 1 = -40mV
CPU GTL Ref 2 = Auto
CPU GTL Ref 3 = -40mV

How can i calculate NB GTL ?