The performance of message passing architecture machines is often ameliorated by devising alternative message passing strategies. A number have been proposed for incorporation into the design of architectures for massively parallel machines. Among these approaches are (i) static machine topologies supporting packet switched message routing (store-and-forward) (ii) dynamic machine topologies supporting circuit switched routing and (iii) shared memory systems. This paper reports the results of analytical modelling of these strategies - verifying the results by experimentation on a large reconfigurable transputer machine (the ParSiFal T-Rack). A family of hybrid architectures called the Hyper-Dynamic Architecture is then proposed which incorporates both packet switched and circuit switched features. Extrapolation of the verified analytical models and various simulation results obtained under realistic environments then allow some prediction of the potential performance of such architectures.