PIK Report No.29

4. Conclusions

For a good performance of a parallel program a good performance of I/O operations is absolute essential. A factor for efficient input/output processing is the suitability of I/O files for parallel file processing algorithms. GRIB files are not very suitable for parallel

I/O processing. Therefore we try to avoid the use of them as far as possible.

A still unsolved problem is the problem of load imbalances. With a static domain decomposition and fixed local data for every processor node it is impossible to balance unpredictable workloads. Static load imbalances are not so important and are better to manage. Future work will study the possibility to solve all balancing problems with only one approach, the approach of dynamical distributed subdomains to the nodes corresponding to their workload. This approach could also be a way to manage irregular grids.