About This Manual

This publication documents the Cray Message Passing Toolkit and Message Passing Toolkit for IRIX (MPT) 1.3 implementation of the Message Passing Interface (MPI) supported on the following platforms:

IRIX systems running MPI applications must also be running Array Services software version 3.0 or later. MPI consists of a library, a profiling library, and commands that support MPI. The MPT 1.3 release is a software package that supports parallel programming across a network of computer systems through a technique known as message passing.

Related Publications

The following documents contain additional information that might be helpful:

  • Message Passing Toolkit: PVM Programmer's Manual

  • Application Programmer's Library Reference Manual

  • Installing Programming Environment Products

All of these are Cray publications and can be ordered from the Minnesota Distribution Center. For ordering information, see “Obtaining Publications.”

Other Sources

Material about MPI is available from a variety of other sources. Some of these, particularly World Wide Web pages, include pointers to other resources. Following is a grouped list of these sources:

The MPI standard:

  • As a technical report: University of Tennessee report (reference [24] from Using MPI: Portable Parallel Programming with the Message-Passing Interface, by Gropp, Lusk, and Skjellum)

  • As online PostScript or hypertext on the World Wide Web:


  • As a journal article in the fall issue of the International Journal of Supercomputer Applications, volume 8, number 3/4, 1994

  • As text through the IRIS InSight library (for customers with access to this tool)


  • Using MPI: Portable Parallel Programming with the Message-Passing Interface, by Gropp, Lusk, and Skjellum, publication TPD-0011


  • comp.parallel.mpi

Obtaining Publications

The User Publications Catalog describes the availability and content of all Cray Research hardware and software documents that are available to customers. Customers who subscribe to the Cray Inform (CRInform) program can access this information on the CRInform system.

To order a document, call +1 651 683 5907. Silicon Graphics employees may send electronic mail to [email protected] (UNIX system users).

Customers who subscribe to the CRInform program can order software release packages electronically by using the Order Cray Software option.

Customers outside of the United States and Canada should contact their local service organization for ordering and documentation information.


The following conventions are used throughout this document:




This fixed-space font denotes literal items such as commands, files, routines, path names, signals, messages, and programming language structures.


Man page section identifiers appear in parentheses after man page names. The following list describes the identifiers:


User commands


User commands ported from BSD


System calls


Library routines, macros, and opdefs


Devices (special files)




File formats


Miscellaneous topics


DWB-related information


Administrator commands

Some internal routines (for example, the _assign_asgcmd_info() routine) do not have man pages associated with them.


Italic typeface denotes variable entries and words or concepts being defined.

user input 

This bold, fixed-space font denotes literal items that the user enters in interactive sessions. Output is shown in nonbold, fixed-space font.

[ ] 

Brackets enclose optional portions of a command or directive line.


Ellipses indicate that a preceding element can be repeated.

In this manual, references to Cray PVP systems include the following machines:

  • CRAY C90 series

  • CRAY C90D series

  • CRAY EL series (including CRAY Y-MP EL systems)

  • CRAY J90 series

  • CRAY Y-MP E series

  • CRAY Y-MP M90 series

  • CRAY T90 series

Silicon Graphics systems include all MIPS based systems running IRIX 6.2 or later.

The following operating system terms are used throughout this document.




Operating system for all configurations of Cray PVP systems


Operating system for all configurations of CRAY T3E systems


Operating system for all configurations of CRAY T3D systems


Operating system for all configurations of MIPS based systems

The default shell in the UNICOS and UNICOS/mk operating systems, referred to in Cray Research documentation as the standard shell, is a version of the Korn shell that conforms to the following standards:

  • Institute of Electrical and Electronics Engineers (IEEE) Portable Operating System Interface (POSIX) Standard 1003.2-1992

  • X/Open Portability Guide, Issue 4 (XPG4)

The UNICOS and UNICOS/mk operating systems also support the optional use of the C shell.

Cray UNICOS version 10.0 is an X/Open Base 95 branded product.

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