and scheduling systems became apparent. Systems such as DQS from Florida State were developed and worked very well. Today, supercomputers, such as Argonne National Laboratory's IBM SP system, can provide more CPU and networking speed than can be obtained from these networks of workstations. These modern

We describe pHPF, an research prototype HPF compiler for the IBM SP series parallel machines. The compiler accepts as input Fortran 90 and Fortran 77 programs, augmented with HPF directives; sequential loops are automatically parallelized. The compiler supports symbolic analysis of expressions

Scheduling jobs on the IBM SP2 system is usually done by giving each job a partition of the machine for its exclusive use. Allocating such partitions in the order that the jobs arrive (FCFS scheduling) is fair and predictable, but su ers from severe fragmentation, leading to low utilization

This report focuses on the development of a series of performance models, together with some examples of using these models, which provide a basis for these experiments and for future porting and tuning efforts on message-passing systems in general, and the IBM SP2 in particular. We have realized

Parallel computer architectures require innovative software solutions to utilize their capabilities. This is true for system software no less than for application programs. File system development for the IBM SP product line started with the Vesta research project, which introduced the ideas

in the network. We describe the route selection algorithm used in the IBM 9076 SP1 multicomputer. We then describe a new algorithm for reducing network congestion and compare the two algorithms. 1 Introduction Scalable multicomputers are based upon interconnection networks that typically provide multiple

: : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 6 2.4 PCN : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 7 2.5 Portable, Extensible Tools for Scientific Computing (PETSc) : : : : : : : : 7 2.6 Porting the p4 Parallel Programming System to the SP-1 : : : : : : : : : : 7 3 Applications 8 3.1 Massively Parallel

: : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 6 2.4 PCN : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 7 2.5 Portable, Extensible Tools for Scientific Computing (PETSc) : : : : : : : : 7 2.6 Porting the p4 Parallel Programming System to the SP-1 : : : : : : : : : : 7 3 Applications 8 3.1 Massively Parallel

The objective of this paper is to develop models that characterize the communication performance of a messagepassing multicomputer by taking the IBM SP2 as a case study. The paper evaluates and models the three aspects of the communication performance: scheduling overhead, message-passing time

This technical report describes the design, implementation, and evaluation of Active Messages on the IBM SP-2. The implementation benchmarked here uses the standard TB2 network adapter firmware but does not use any IBM software on the Power2 processor. We assume familiarity with the concepts