Forgot to post this result, so thought i'd do it now. First screenie is 5ghz stable with the E8600. Second screenie at 5.1ghz is where it is at the moment, i'm pretty shure it'll run the distance. As you can see, nice low Vcore so it should have a bit more headroom in it yet

5ghz 8hrs Orthos blend stable:


5.1ghz Orthos blend, still running: