The speed at which the process will be executed doesn't depend only on the implementation of the architecture of the computer, the frequency of the clock, but also regard to the politics the algorithm follows and the data structure the algorithm is implemented. The usage of efficient page replacement algorithms, that choose which page in memory will be swapped if a page fault, are required to implement in a virtual memory system. A lot of algorithms are developed during the years for page replacement. Each algorithm has the aim to have less number of page faults. With less page faults we have an improvement in performance and the speed of the process is increased. In this paper three algorithms (FIFO, LRU and Optimal page replacement algorithms) will be tested and will be shown the one that has the best performance.