A server constituted by a plurality of processors which process page description language data receives a print instruction from a client, and decides the number of layers into which a page is to be segmented based on render instructions included in the page description language data. The server decides the number of processors which perform parallel processing of the generation of print data from the page description language data based on the decided number of layers. The server generates print data equal in number to the number of layers based on which the number of processors is decided. An output device requests the server to transmit print data. The server transmits print data in accordance with the request from the output device. Upon receiving the print data from the server, the output device processes the print data and outputs it onto a sheet.