A Study of the Periodic Performance Degradation of Flash Memory Write Operations in Smartphones

Flash memory is widely used in many smartphones. It has been reported that its write performance periodically degrades significantly. In this paper, we study the behavior of significant write performance degradation in smartphones and show that its interval depends on the I/O block size and the number of byte sizes in the written and unwritten areas. We then provide a method for predicting the next significant performance degradation based on this interval. As an application, we discuss a method to avoid the significant performance degradation by performing a dummy write operation.