Well I have not used P55 yet, so I am stabbing in the dark really but my thoughts are based on helping others and what I have seen out in the wild, so not completely blind I guess.

What board are you using anyway? If it is a Gigabyte board I can tell you to be sure you try all the Performance Enhance settings, because sometimes Turbo or Extreme can be far more stable then Standard as one might expect from previous boards.

Anytime man, hope some of what I suggest will help you out a bit!