AbstractThis paper studies the performance of a multi-processor computer system, which can be used to execute multiple number of SIMD jobs. Such parallel computer organization contains multiple Control Units (CUs) which share a resource pool of a finite number of Processing Elements (PEs) and operate multiple single-instruction-multiple-data streams (MSIMD).A closed queueing network model of a MSIMD computer system is simulated. In order to investigate the effect of the vector jobs size on the system performance in two different CPU queueing disciplines and for various degrees of multiprogramming, different methods of allocating PEs to CUs are considered.