ok my stock QPI is 1.2. I tried that and it failed to POST. So, I loaded my saved O.C. profile from my BIOS but this time I changed the PLL voltage from 1.8 to 1.82 and I changed the RAM speed to 1363 (x8 multi). So my settings are the following
Multiplier: x21
Base Clock: 170
DRAM Freq: 1363
Vcore: 1.325
PLL: 1.82
QPI: 1.35
IOH 1.1(only 1 graphics card)
DRAM 1.5
Load Line Calibration enabled
All spread spectrums disabled
All C-state/Power saving features disabled
Turbo Boost disabled
Upon loading these settings, the computer auto shutdown, rebooted, Posted, and loaded the desktop without any black artifacts.
I proceeded to Shutdown the PC 5 times, rebooted, Posted, and loaded the desktop without any black artifacts each time. For me, these indicators are a sign that the overclock is stable. I still need to run Prime95 and/or Intel Burn Test but I know the behavior of my machine well enough to know that if I have these positive indicators that I mentioned before, then it's most likely stable and will pass any stability test.
We'll see if the increase in PLL voltage makes a difference. I'll post back if it fails. If not I'll post anyways.
Let me know what you think.