User data persistence in physical memory

In this paper we present the results of experiments we conducted on Suse Linux and Windows XP systems to determine the age of user process data in physical memory. To be able to measure the age of pages we used an artificial load program which time-stamps data segment and block device cache pages. Our goal was to compare the behaviour of both systems and to determine whether the rate of decay for user data depends on the demand for physical memory. Our findings show that Windows and Linux systems preserve almost the same number of pages with user data, and the age distribution of these pages does not change significantly with the level of demand.