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LAM/MPI Parallel Computing

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Do you like LAM/MPI? Then check out Open MPI!

LAM/MPI is now in a maintenance mode. Bug fixes and critical patches are still being applied, but little real "new" work is happening in LAM/MPI. This is a direct result of the LAM/MPI Team spending the vast majority of their time working on our next-generation MPI implementation -- Open MPI.

Although LAM is not going to go away any time soon (we certainly would not abandon our user base!) -- the web pages, user lists, and all the other resources will continue to be available indefinitely -- we would encourage all users to try migrating to Open MPI. Since it's an MPI implementation, you should be able to simply recompile and re-link your applications to Open MPI -- they should "just work." Open MPI contains many features and performance enhancements that are not available in LAM/MPI.

Make today an Open MPI day!

LAM/MPI: Enabling Efficient and Productive MPI Development

LAM/MPI is a high-quality open-source implementation of the Message Passing Interface specification, including all of MPI-1.2 and much of MPI-2. Intended for production as well as research use, LAM/MPI includes a rich set of features for system administrators, parallel programmers, application users, and parallel computing researchers.

Cluster Friendly, Grid Capable

From its beginnings, LAM/MPI was designed to operate on heterogeneous clusters. With support for Globus and Interoperable MPI, LAM/MPI can span clusters of clusters.


Several transport layers, including Myrinet, are supported by LAM/MPI. With TCP/IP, LAM imposes virtually no communication overhead, even at gigabit Ethernet speeds. New collective algorithms exploit hierarchical parallelism in SMP clusters.

Empowering Developers

The xmpi profiling tool and parallel debugger support (e.g., using TotalView or the Distributed Debugging Tool) enable in-depth application tuning and debugging. Debug-compile-run cycle times are greatly reduced with LAM’s fast job start-up.

A Stable Extensible Platform for Research

The new component architecture available starting with version 7.0 enables developers to incorporate new functionality into LAM/MPI—without having to understand its internal details. By writing to LAM/MPI’s system services interface, researchers can readily add support for new transport layers, new collective algorithms, boot protocols, checkpoint/restart, and more.

Tools and Third Party Applications

Since LAM/MPI implements the specified MPI standard, most third-party parallel applications based on MPI will "just work." In addition, a number of auxiliary tools are available for LAM/MPI.

Make Today a LAM/MPI Day!

Everything you need to get started with LAM/MPI is right here. Follow the links on the main menu to download and install the software. You can also find a wealth of documentation and tutorials on parallel programming with MPI, as well as information on using LAM/MPI with third-party parallel applications. If you need help, we have help pages, a FAQ, and active mailing lists.
LAM/MPI 7.1.3 Released

Bug fix release; see the HISTORY file for details.

> Release announcement
LAM/MPI 7.1.2 Released

Bug fix release; see the HISTORY file for details.

> Release announcement
Open MPI Announced

An all-new MPI-2 implementation. Be sure to see the web site:

Features at a Glance
System Administrators
PBS Integration
Bproc Integration
SLURM Integration
Globus Enabled
Parallel Programmers
Complete MPI 1.2 Functionality
Extensive MPI 2 Functionality
TotalView Support
Application Users
High Performance
Ultra-Fast Job Launch
SMP Aware
Myrinet Transport
Infiniband Transport
Interoperable MPI
Parallel Computing Researchers
Extensible Component Architecture
Quality Software That Works
Platform Portability