1. In a multi-rank DDRx memory system having at least two ranks of memory each having a number of banks, where x is an integer greater than or equal to 2, a method for performing command scheduling for row access commands and column access commands, said method comprising: decoupling the row access commands from the column access commands; alternatively scheduling the decoupled row access commands to different ranks of the at least two ranks of memory; and group scheduling the decoupled column access commands to each bank of the number of banks of a given rank of the different ranks of the at least two ranks of memory.