Connections between priority queueing models and computer architectures are widely known. But, as far as we know, there was no formulation of exact models for sufficiently general computer architecture models. This paper has two goal: the first and the smaller one is just to give this formulation in exact mathematical terms. The second and the most important one is to present a new approach to priority networks themselves. This approach is based on recent advances in the dynamical system approach to queueing networks, which in some very particular cases becomes a well-known fluid approximation. This gives a new approach to evaluate performance of a given computer architecture. We apply this method here to the simplest architecture with the unique bus. This paper can be considered as the first step in the development of this approach.
Key words: computer architectures, priority queueing systems, dynamical systems, fluid approximation.