So far, performance measures for real time systems did not receive much attention. An assessment of the few existing benchmarking methods for real time systems will reveal that they are highly inappropriate. After the characterstics of real time cluster is analysed we define a number of the measuring performance criteria.. We developed simple and effective test approachs of real-time cluster for low-Level. Finally we give the test results of real-time cluster in laboratory and prove they are effective test approachs..