Universit?t Dortmund, GermanyPerformance analysis of multiprocessor architectures in the early design phases is an important task in the develop- ment of complex parallel architectures. An approachfor the hierarchical modeling and analysis of a wide class of mul- tiprocessor architectures is introduced. The technique com- bines and extends several efficient approaches to analyze large CTMCs underlying hierarchical models of multipro- cessor systems. First, the generator matrix is represented in a very compactformat which can be exploited in efficient nu- merical solution techniques. Second, symmetries inherent in most multiprocessor systems can be exploited by generating CTMC with a smaller state space, which results from exact aggregation, Symmetry exploitation is fully automated and keeps the compact representation of the generator matrix.