Testing the limits of my Lightning under cold with Vmem mod.
While I'm not happy with some of the limits, I can't say I'm too displeased so far. Since my CPU is still under SS for now, I only played with 3D03 - Trolls and Nature pretty much give me an idea.
1)
Cold Bug -120 
2)
GPU 1360 max clock to complete Trolls. Does at 1.51v. Can't clock higher with 1.55v, but that's as much as I wanted to push it this early on.
3)
Mem 1300 max clock to complete Nature, though hit or miss. 1290 max for consistency.
4)
1.72v absolute max Vmem. Can see pixels fall out predictably while in 2D at 1.72v. I kept at 1.67v for rock stability.
I'm gonna bench it like this for a while before doing OCP and VDDCI mods. Baby steps. Killed too much expensive hardware lately to risk losing out on some quality benches before jumping to suicidal stuff.