I wonder why your voltages are so high? I know quads take a bit more voltage than dual cores, but some o/c'ers have better luck with lower voltages. I would check out the numerous threads about Q6600 and the 45nm Quads o/c'ing for some tips...If I remember correctly there seems to be a FSB wall around 450 with the Quads.

I have the P5K Deluxe and the LLC does work. I think it keeps the actual voltage closer to what you set in the bios. vDroop under load is another matter. My P5K has a consistent .008v drop under full load as compared idle voltages. No matter what I set the cpu voltage to, I always get a .008v vDroop. I always have LLC enabled. I wonder if your power supply is being overtaxed? I have a 600w Fortron.

With my E3110 @ 4100 MHz (513 x 8), I set 1.3875v in bios which shows as 1.368v at idle, and 1.36v at full load. Here are my voltage settings which are 100% stable:

Asus P5K-D/E3100

cpu: 1.3875v
ram: 1.9v @ 1026 MHz - 5-5-5-12 timings
VTT: 1.1v
PLL: 1.5v
NB: 1.25v
SB: 1.05v
cpu GTL: auto
nb GTL: .61x

Bootstrap: 400 MHz
Loadline Calibration: enabled
Overcharge voltage: disabled
Slews: auto
Transaction Booster: enabled, "2" boost = PL9 (I would set this to disabled while testing)