What you are looking at is modifying memory timings, also occasionally referred to as "changing latencies" - I've seen other people call it that also.
I'd start with step 2 in our guide:
http://www.overclockers.com/3-step-guide-overclock-core-i3-i5-i7/
If you understand what its talking about there, that gives you a start for how to deal with modifying your memory timings.
Here's a solid explanation of what these timings actually are/mean:
http://www.amd.com/us-en/Processors/ComputingSolutions/0,,30_288_13265_13295^13335,00.html
From that, you can start to tighten things up and see what's stable and what isn't. You'll find this depends on what your memory is rated for, as well as what frequency you are running at - with a lower frequency, you can run tighter timings, with a higher frequency, you may have to loosen timings.
With more specific information about the hardware including CPU, memory brand/model, and motherboard you are working with, someone may be able to give you more specific advice than I could.
EDIT: By the way, I linked the signature rules in your sig, the canardpc links aren't permitted here. We have stricter sig rules than most sites. No problem, just a heads up.
