Mad Shrimps posted a guide about stabilizing your memory overclock on Core i7 platform
>> Stabilizing your memory overclock on Core i7 platform
In today's short article, we'll have a look at the effect of just one memory timing, the Back-to-Back Cas Delay timing, which seems to be one of the more important timings both performance and stability-wise. If you're looking for a solution for your high-frequency capable memory kit, performance increase with low-frequency memory or stabilizing high BCLK/high memory ... this is something for you.
>> Stabilizing your memory overclock on Core i7 platform