Abstract: Schedulability test is a key problem for real-time scheduling algorithms. Since first introduced by Liu and Layland in 1973, the RM (rate monotonic) algorithm and its extended ones have been widely used in many fields such as digital control, command and control, signal processing, and communication systems. A lot of work has been done to investigate their schedulability, and present their corresponding schedulability tests. As the implementation of real-time systems requires the consideration of the practical issues such as the number of tasks, the period of each task, and scheduling costs, a systematic performance analysis platform is required to give them a thorough evaluation. In this paper, all schedulability tests of RM and its extended ones are summarized, a platform is developed to test and compare their performance, and a thorough evaluation and comparison is made of the schedulability tests through testing. These results and analysis are very beneficial for selecting appropriate algorithms in real-time system design and implementation.