A non-transitory computer-readable storage medium having stored therein a program for causing a computer to implement a method of controlling an image reading apparatus including a reading unit configured to execute a reading job for reading an image on an original, and an image processing unit configured to perform image processing to the image read by said reading unit, the method comprising:
- an acquisition step of acquiring identification information about the image forming apparatus;
- a determination step of determining whether or not the acquired identification information is included in a first table in which clock frequencies for respectively controlling hardware of a plurality of reading units are set for each of a plurality of pieces of identification information;
- and
- a setting step of setting a clock frequency for controlling hardware of the reading unit in accordance with the first table and the acquired identification information when it is determined that the acquired identification information is included in the first table, while setting the clock frequency for controlling the hardware of the reading unit to a predetermined setting when it is determined that the acquired identification information is not included in the first table.