First results from the parallelisation of CERN's NA48 simulation program

The GP-MIMD2 project aims at demonstrating the effectiveness of using a European massively parallel supercomputer (MEIKO CS-2) in two different scientific production environments. One of its initial goals is the development of a parallel version of NMC, a specialized simulation code (developed by the CERN experiment NA48) which relies on a huge database (shower library) for maximum efficiency. NMC's memory requirements, combined with NA48's need of high statistics on a short timescale, make it a particular interesting candidate for MPP applications. In our staged approach to NMC's parallelisation we decided to start with event level parallelisation (task farming); this was implemented using tasks that communicate via the CHIMP message passing interface. An overview of our initial experience will be given, both with and without access to the shower library. First timing tests and I/O analysis will be described, concluding with plans for future developments.