It was devised to aid the testing and debugging of programs that are either modified in some way, or are ported to other computer platforms. Medium-grained problems generally make better use of expensive HPC resources. F90 code generally runs slower than equivalent F77 code. Don't use F90 features in compute kernels. F90 array syntax hurts performance.
Post receives before sends.
Send BIG messages. The structure of SLOG trace files enables the viewer, Jumpshot, to produce various overviews of the entire volume of data. Users will be presented with greater detail as they zoom in, rather than seeing an expanded view of the same level of detail. Jumpshot is written in Java. The current method for controlling the size of trace-based MPI tool output is to instrument the code.