MB Tweaking to Reduce Vcore

[gerbiaNem]

System is a 4930k at 4.4GHz with Asus x79 Deluxe and 32GB Crucial Ballistix 2133.
One GTX770, one GTX 670 (don't ask), and Xonar Essence STX.

I know a working fix, just seeing if there's a better way of increasing the IMC stability.
I'm 100% stable on Prime95 a 1.230 Vcore until I run an application that uses GPU rendering (including Chrome). It remains stable for a good 30 minutes until it blue screens. Bumping Vcore to 1.32 makes it 100% stable.

VCCSA, VTT, PLL are all at very low voltages, and temps don't go past 75C with H100i at 1.32. PSU is an AX1200i, and volts are stable. Bumping these voltages up doesn't help.

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What CPU tweaks can I try to reduce the Vcore while remaining stable under MB strain (GPU mainly)? I have a feeling the GPU running drops the voltage and causes the instability.

Can I try offset voltage tweaking? LLC? Raising turbo watt limits? Vdroop?
CPU items I need enabled: VT-d, SpeedStep, C States (maybe?)

I know the CPU is stable at 1.23, that's what really bugs me. Any advice from a more experienced overclocker would be greatly appreciated.

 

[gerbiaNem]

Very promising find.

I increased the VCCSA load line calibration to high and dropped Vcore to 1.28 then 1.27.. all the way down to 1.2 at the moment.

An hour of testing video playback, rthdribl, prime95, and not a hitch. Temperature touches 71C on the hottest core.

It's amazing how I've never heard about the VCCSA LLC being such an important element. Maybe 4x8GB ram isn't common enough.