1. An image processing apparatus comprising: a first memory configured to temporarily store data, the first memory having a data reading and writing speed which is higher than a data reading and writing speed of a second memory; a reception unit configured to receive instruction data directing the image processing apparatus to perform image processing; a storage controller configured to store the received instruction data in the first memory if an attribute of the received instruction data meets a predetermined first condition and, otherwise, store the received instruction data in the second memory; and an image processing executing unit configured to execute the image processing indicated by the stored instruction data.