As embedded systems grow in size and complexity, an operating system has become essential to simplify the design of system software, for which more accurate analysis of its impact on memory performance is required. In this paper, we intend to investigate how the OS influences memory performance at run time by quantitatively evaluating the memory system behavior of an MPEG-4 application running on embedded Linux. Through the use of extensive simulations we have confirmed that the OS has poor memory performance with less memory locality than applications. The results of our experimental analysis are deemed useful for helping embedded system designers understand the memory performance of the OS and the application within a system, extending their capability to design a more power-aware and faster system. Categories and Subject Descriptors C.4 [Performance of Systems]: Design studies, Performance attributes; D.4.8 [Operating systems]: Performance—Measurements, Simulation General Terms...