CHIV bios
CPU Voltage = vcore under 1.55 at 50+C load.
CPUNB Voltage = IMC 1.4-1.5 should get yuou some mondo CPUNB clocks under cold. Like 4000MHz
HT Voltage is your hypertransport link to the PCIE slots (and depending on what elese is connected on that motherboard, sometimes LAN, audio, USB etc) I HTREF clock a lot this is essential for that EVEN if you drop the HTLink speed...
1.35 usually stabilizes everything out up to high 5Ghz
NB voltage I forget what this is... I want to say chipset but I think that is the next voltage I usually keep this one at near CPUNB voltage
NB 1.8= chipset. Wont need much here... 1.9-2.0 if anything at all more HTREF really... but.. I always bump iot
SB voltage 1.3-1.35 fro stabilizing raid and other peripherals off the SB when HTREF clocking. Should not need to adjust this much at all up to 240HTREF.
Sure you know what VDDA and REF voltages are.
Microcode update, I have tried on or off. Makes no difference that I can tell...
Core Unlocker/Activation... disabled of course...
I never pushed more than 1.6 - 1.7 on vcore even on LN2, as I could not afford to kill the chips, and also because my system was crashing for other reasons. According to Chew when clocking AM3
"the blue screen is NB vid/IMC memory related, the black screen is core clocks/cpu voltage related and the just crash/dissapear from desktop is temp related"
BSOD I usually go by the stop error code ... black screen = CPU and freeze/ crash to desktop... unstable but still pushable

could be any number of things really depends on the bench I was running.
You can take that for what it is worth though.
Oh also I thought a coorelation between vcore + cpuNB vid = VDDA might be worth trying out.. not cast in stone though