Make sure your RAM voltage is up where it's supposed to be also. For example, my RAM is 2.2v stable but my mobo defaults at 1.8v. Also, your RAM timings seem loose at 6-6-6-18. After you think your system is stable, you can maybe tighten them to 5-5-5-15. That's what I'm running, and my e6600 is 3.6ghz.
This might not have anything to do with your RAM however. Your vcore might be too low if you can't run Crysis but a few minutes. So if your temps are good, you have some headroom to up the vcore.
Ok, thanks a lot man! What is your voltage at on your board? I want a general idea of where my voltage should be close to. Is there a voltage that is so high it nears a danger point for hurting your PC?