Abstract: A method for transferring a command from a host to a device controller and a system using the method are disclosed. The method includes the steps of: A. determining a segment size; B. dividing a command into a number of sections each having a size the same as the segment size; C. sequentially distributing the sections to n groups; D. changing distributing order to a reverse order or keeping the same distributing order in step C if a cycle of distribution is finished while there are sections left for distributing; E. restructuring the section(s) in each group as a sub-command after all sections are distributed; and F. providing the sub-commands to a device controller synchronously.