Lawrence Berkeley National Laboratory

Partitioned Global Address Space (PGAS) Languages are an emerging alternative to MPI for HPC applications development. The GASNet library from Lawrence Berkeley National Lab and the University of California at Berkeley provides the network runtime for multiple implemen tations of four PGAS Languages: Unified Parallel C (UPC), Co-Array Fortran (CAF), Titanium and Chapel. GASNet provides a low overhead one-sided communication layer has enabled portability and high performance of PGAS languages. This paper describes our experiences porting GASNet to the Portals network API on the Cray XT series.