Xtreme Resources have got a great guide up to tweaking TCCD memory modules on the DFI nForce4 platform.
As we all know, the DFI range of boards are the overclockers choice for nForce4, with an amazing amount of BIOS options and tweaks that can be used to obtain the absolute maximum performance.
The Xtreme Resources guide uses the much talked about G.Skill memory modules along with an inexpensive Winchester 3000+, a chip which is known to be a great overclocker. It includes the best BIOS settings for the modules, down to the smallest details, as well as some tips for overclocking newer San Diego cores.
The guide aims to take you to DDR600 and over, with such nuggets as "Decreasing the DQS Strobe timing gives the memory a huge stability boost, and little performance loss."
If you can stomach all the tweakery, there's some definite gold in there, and it's well worth a look even if you're not using TCCD on DFI, because some of the principles mentioned are universal.
You can check out the guide here