I'm actually a pretty timid OC'r. Guess thats why I never put up any really impressive numbers...

I tend to do things VERY slowly, and when I get to a point where increasing voltages only shows a marginal performance boost, I call it good.

Temps can definetly be a problem, and anything over 53c on the cores has been unstable for me on almost every Phenom I've had....

Granted I've never worked with extreme cold, but under water and aftermarket air I've found that temps don't seem to be the only limiting factor.

My WC rig now can keep temps under 50c up to 1.6v's. Anything over 1.525 on the core, and 1.3 on the IMC doesn't seem to help though, reguardless of temps.

C2's seemed to be a little more tolerant of high V's, but I have 2 C3's and neither one of them really benefits from CPU-NB v's >1.3v or Core v's >1.525 even at temps under 50c...

From what I've seen things seem to be really different when using extreme cooling (Dice/Ln2), but for folks using more conventional cooling just keep in mind that temps may not be the only limiting factor...