powergiga08 at 4ghz you would use much lower voltage, 1.344-1.3625. And the performance would be akmost the same.
Your chip is a midddy one, like mine . I have a vid of 1.243v and it can do 4ghz with 1.328v-lod(1.331v bios)-priming 2-3hours(in signature 1.312v it can do about 40 minutes). I don't think that it would go with less voltage on other boards.