Lowest voltage for overclocking i7 920 to 3.2Ghz

I am wondering what is the lowest possible voltages, including vcore, QPI, and etc, such that you can overclock the i7 920 to a stable 3.2Ghz.

Any help will be appreciated, thanks a lot.

Currently, I have the following setting in my Asus P6T bios:

AI Overclocker Tuner: [Manual]
CPU Ratio: [Auto]
Speed-step: [Enabled]
BLCK Frequency: [160]
PCIE Frequency: [100]
DRAM Frequency: [DDR3-1604 MHz]
UCLK Frequency: [Auto]
QPI Link Data Rate: [lowest one]

DRAM Settings:
8-8-8-24

Voltages:
Vcore [1.15]--I may be able to go lower, but unstable at 1.00 for sure.
CPU PLL Voltage: [Auto]
QPI/DRAM Core Voltage: [Auto] -- Is there anyway that I can check how much this indeed is?
DRAM Bus: [1.64]
Rest on auto

Every single chip is different. So there isn't a specific voltage you can use for every chip for a given OC. I don't know what the general range is for the core i7. but typically in you situation you may need to either up the voltage or turn down the clocks.

I got it stable at 1.175 vcore for 3.2Ghz on my D0 920.
Ram is running 1600 with QPI voltage 1.3.

But I figure the faster ram doesn't really help in performance, so I slowed it down to 1066 default speed, and lower the QPI and Dram Bus voltage to [Auto], but has a slightly tighter timing. This way, the temperature is lower by about 2C.
:0

I have a p6t V2, and I use the Auto settings, with the same BCLK, 160. Put your QPI at maximum to improve memory bandwidth. Hope all this was useful.

It's a shame that the chips are always different, because helping with advanced overclock gets hard. If you have any problem, remember to put avery possible setting on AUTO and then change them in order to get a more stable OC.

You're welcome.