Dram CLK Driving Strength (DS)
Dram Data Driving Strength (DDS)

DS and DDS are the signal strength settings for the ram.

Ch1 DLL Default Skew and Ch2 DLL Default Skew are the tables for the various type of ram used. Both should almost always be set to the same model.

All four of these settings will have a large influence on stability, max FSB and board voltages. Set wrong and the board may not even boot.

The added MCH option should not be adjusted. Most users will have no clue what each does and the values input needs to be in hexadecimal form. The Fine Delay Stepping changes the value for the clock skews. The default was 70ps now it's user selectable. But this is a global setting and applies to all clock skews.

For a lot of users these additional settings requiring user input is going to be more then they want to mess with.