Thx for the datasheet I couldn't find it. Max safe value for VVT has actually gone up That's really good news.

The Uncore on my X5650 is stuck at x20 no matter what x3, x8 or x10 RAM, or QPI-multiplier I set in BIOS. Both CPU-z and CPU-tweaker are reporting Uncore=x20 all the time . I don't trust any of these to be totally correct yet, and it may be a UD7-BIOS-bug too, but can it be some kind of Xeon DP locked Uncore too?

Whatever the reason, I have to find out later, but right now I'm using VVT~=1.38v for 4GHz and it is good to see it is within Itel's safe limits.