When we consider large scale systems, it is important to be able to modelling and simulation is required at least with partial functionality and we should be able to evaluate the performance before designing the architecture. A lot of tools are available in connections with workstations and parallel architecture for large scale parallel virtual machines common to evaluate different models. The appropriate representation of the computer architecture model is very important. M.J. Flynn, who has guided the categorisation of the multiprocessor configuration, has specifically enveloped the model for parallel processing which has a row of processors and row of memory elements with an appropriate model within them. 2D and 3D computer arrays are considered in the model. There is one problem, that is the appropriate representation of the neighbouring processor in 2D and 3D representation. But representation of neighbour processors and interaction in array is exponential with number of CPUs. The interconnections increase exponentially. This is a very critical issue. It is still an open problem for researchers.

---