Have you download the last Bios for the Asus P6T Deluxe V2 -> 0302 !! i run now at 3.930Ghz (19x207) with 1.25625Vcore in Bios.
3.8Ghz has enough with 1.1875V thanks to the new Bios 0302 .With the first one 0102 the cpu needed alot more vcore to reach these speeds!