Abstract The Geometric Arithmetic Parallel Processor (GAPP) is a systolic planar array processor with 72 (6 × 12) processing elements arranged in a mesh network. It runs at a clock speed of 10 MHz. The greatest advantage of such a design is that as many processor chips as are needed can be implemented without the loss of processing speed as interprocessor communication has been designed into the hardware architecture. It is therefore particularly suitable for processing of large image files with SIMD type of program execution. In this paper we report our study of the GAPP's performance in comparison with a number of other array processor systems, including: CLIP4, ICL DAP and Goodyear MPP. We also compare GAPP with some DSPs such as TMS32020, INMOS Transputer. We have found that GAPP's performance is in the same order of magnitude as these processors.