unlocking cores indivually? and RAM timing?

What benchmark are you using? As for unlocking & further overclocking set the core voltage to 1.5 (maximum 24/7 safe) and see what you can do then lower it as far as you can checking stability with Prime 95 or similar. How to unlock cores separately depends on the motherboard and should be a fairly obvious bios setting.

I bought the same CPU for my son and matched it with a ASUS M4A78E. I tried to unlock all four cores but was only successful in getting one to unlock. The BIOS automagically determined which core(s) could be unlocked. When I set the BIOS to unlock the cores and restarted, the computer hung on power up and didn't reset on it's own. I held the power button in until it shut down, then I powered up again and when it started, it had unlocked one of the cores. It runs fine on 3 cores (now its a triple-cripple) and I can do it at default voltage. It didn't matter what I did though, I couldn't get the fourth to unlock (voltage, various other settings), so it must be very defective. I don't know if other boards are similar, but I imagine they would be. I never tried a software utility to unlock cores, nor do I use them in overclocking. Call me 'old school' but I like to get it done in the BIOS.