The present invention discloses a method of enhancing system performance applicable to a computer system capable of executing a snapshot process. The method includes counting a number of times the computer system has executed the snapshot process; and if the number is smaller than two, updating data made by the snapshot process executed by the computer system with data that are to be changed in the computer system, or updating data made by latest one of the snapshot processes executed by the computer system with the data that are to be changed in the computer system, instead of updating data made by all the snapshot processes with the data that are to be changed in the computer system, so as to save system resources and increase the system performance of the computer system.