An information processing device detects a sequential access for reading first data by sequentially accessing consecutive areas or inconsecutive areas within a specified range of a first storage unit when the sequential access consecutively occurs by a specified number, calculates, based on a size of the first data, a size of second data read by a prefetch for prereading the data stored consecutively in the first storage unit and for storing the read data in a second storage unit, and performs the prefetch based on the calculated size of the second data.