Was easy to do with reasonable voltage.
ambient room: 31-33
full load (prime 95): 69-70
I knew I was cpu limited with the last couple video cards I had but I didn't realize by how much. My framerates basically doubled in Borderlands.
I haven't tried to go higher and I don't feel the need to try. This thing is blazing fast compared to my old opty 165 @ 2.7 I doubt I'd notice a difference even if I went to 4.4ghz