Alright, just be aware that in my case, 10% margin is already "bugged", everything is about to keep the vram in the right spot to be in the legal margin.
And just to avoid people thinking I'm guilty of cheating, This happened with multiple drivers, only on W7, only when the memory is at the limit. I was just pushing without thinking is could be bugged, because it was consistent. Now I'm aware, and hopefully nobody will accidentaly exceede 15% ratio ...