A print data processing system includes plural main interpretation devices that interpret print data described in a page description language and generate print image data to be supplied to a printer, auxiliary interpretation devices that interpret the print data, generate print image data to be supplied to the printer, and are not powered on when the plural main interpretation devices are powered on, and an allocation device that divides the print data in prescribed units and allocates interpretation processing of divided print data of the respective units to the plural main interpretation devices, wherein the allocation device includes a load evaluation unit that evaluates the loads of the plural main interpretation devices, and a power-on unit that, when the loads of the plural main interpretation devices evaluated by the load evaluation unit exceed a prescribed on threshold value for activating the auxiliary interpretation devices, powers on the auxiliary interpretation devices.