A Comparison of the Iserver-Occam, Parix, Express, and PVM Programming Environments on a Parsytec GCel

We compare the Iserver-Occam, Parix, PVM, and Express parallel programming environments on a Parsytec GCel with 512 T805 transputers. The comparison will be made by a detailed analysis of the performance of one particular application. In our approach we start with this application and isolate the basic (environment dependent) building blocks. These basic building blocks, which depend on floating point performance and communication capabilities of the environments, are analysed independently. We have measured point to point communication times, global communication times and floating point performance. All information will be combined into a time complexity analysis, allowing us to compare the environments on all relevant degrees of functionality. Together with demands for portability of the code, and development time (i.e. programmability), an overall judgement of the environments can be made.