A booting method of a computing system, which includes a memory module including a processing device connected to a plurality of memory devices, including: powering up the computing system; after powering up the computing system, performing first memory training on the plurality of memory devices by the processing device in the memory module, and generating a module ready signal indicating completion of the first memory training; after powering up the computing system, performing a first booting sequence by a host device, the host device executing basic input/output system (BIOS) code of a BIOS memory included in the computing system; waiting for the module ready signal to be received from the memory module in the host device after performing the first booting sequence; and receiving the module ready signal in the host device, and performing a second booting sequence based on the module ready signal.