Tekken 4 and 5 are some of the most intensive games to run using PCSX2. You might be able to run the Tekken Force aspect of the game with some decent speed, however the main game will probably struggle at around 20fps (at an estimate). To get the most out of Tekken 5 you need at least an E8400 which has been overclocked due to how intensive the CPU has to work to get the game to work.