Local vs. global memory in the IBM RP3: experiments and performance modelling

A number of experiments regarding the placement of instructions, private data and shared data in the Non-Uniform-Memory-Access multiprocessor, RP3, have been performed. Three scientific/mathematical workloads have been used in the experiments, and the results have been modelled in a simple performance model which takes linear contention into consideration. The results indicate that it can very well be feasible not to have memory local to the processors in RP3-like architectures. There seems to be a trade-off between the effort spent in the design on the memory system and the interconnection network and the use of local memory which can be costly in terms of prohibited process migration and more complicated software management