What I found with Intel's XMP settings was that they were far more aggressive than they needed to be. But it's a starting point to start lowering select items from. Volts are what kill hardware, and that's one I found far too aggressive. It's a bit backwards from baby-steps up (since you're going down) but may be a valid option if you like some of the speeds you're currently offered. On that one, I was able to drop the CAS one full notch across the board, get the CPU volts back to suggested "safe" levels, and remain at the 1800Mhz memory / 3.8Ghz CPU speeds XMP had set for me.
SB will be a piece of cake. Just think really hard about adjusting any volts or offsets/skews. If you get the K-version, you'll be at 4Ghz in no time without touching a voltage setting or buying heatsinks.
these tips are Intel CPU-related ? cuz this thread is about AMD Phenom II X4. But since I will be building a sandybridge when my PSU arrive, thanks for the tips too