In a very short forum thread, Splave explains the common practice of "training" your memory configuration for the best possible performance. He uses the Samsung IC as example, the the same principles apply to all types of memory. Essentially, it comes down to what we already knew from the X58 platform. The RTL value plays a significant role in optimising the performance of your memory subsystem. Sometimes even motherboards with the best tuned autotables will miss the optimal RTL value for a certain configuration after training, resulting in lower than expected performance.

Splave's step by step process:

• First off lets go into the memory configuration page and at the bottom disable MRC fast boot so that memory will train on each boot.
• Then go ahead and apply 2666 profile for samsung in the memory config page as well as setting 2666 memory divider.
• Resist the urge to tighten the settings "You know" will be faster for now.
• Instead apply the settings and save and exit to allow it to train at 2666.
• Go back into bios and check out where your RTL and IO-L are at. They should be approx 42/43 4/4.
• Okay so now lets go back into bios and set 2800 and see where they lay. Should be around 47/43 9/4

Enjoy your freshly improved performance!

More information in the forum or check out the original post at XtremeSystems.