For 3.4GHZ I did this:
333/667
CPU
VID Special Add: +25.0mV
DRAM Voltage Control: 2.100V
SB Core/CPU
PLL Voltage: 1.510V
NB Core Voltage: 1.392V
CPU
VTT Voltage: 1.100V
Vcore Droop Control: Disabled
Clockgen Voltage Control: 3.45v
GTL+ Buffers Strength: Strong
Host Slew Rate: Weak
MCH Ron Offset Value: 00
MCH RTT Offset Value: 00
MCH Slew Rate Offset Value: 00
MCH VRED 1 Value: 00
MCH VRED 2 Value: 00
MCH VRED 3 Value: 00
x CPU GTL1/3
REF Volt: 0.667X
x CPU
GTL 0/2
REF Volt: 0.667X
x North Bridge
GTL REF Volt: 0.67X