Intel® MPI Library Release Notes for Linux* OS

ID 914349
Updated 4/28/2026
Version
Public

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Overview

Intel® MPI Library for Linux OS* is a high-performance interconnect-independent multi-fabric library implementation of the industry-standard Message Passing Interface, v4.1 (MPI-4.1).

To receive technical support and updates, you need to register your product copy. See Technical Support below.

Key Features

This release of the Intel(R) MPI Library supports the following major features:

  • MPI-1, MPI-2.2, MPI-3.1, MPI 4.0 and MPI 4.1
  • Interconnect independence
  • C, C++, Fortran 77, Fortran 90, and Fortran 2008 language bindings
  • Amazon* AWS/EFA, Google* GCP support
  • Intel® GPU pinning support
  • Intel® and Nvidia* GPU buffers support
  • PMIx Support

Product Contents

  • The Intel® MPI Library Runtime Environment (RTE) contains the tools you need to run programs including scalable process management system (Hydra), supporting utilities, and shared (.so) libraries.
  • The Intel® MPI Library Development Kit (SDK) includes all of the Runtime Environment components and compilation tools: compiler wrapper scripts, include files and modules, static (.a) libraries, debug libraries, and test codes.

You can redistribute the library under conditions specified in the License.

What's New

Intel® MPI Library 2021 Update 17.2

  • Bug fix: Fix a TCP related performance regression in libfabric.

Intel® MPI Library 2021 Update 17.1

  • Bug fix: Fix a performance issue when using shared memory transport provided by libfabric providers instead of the built-in Intel MPI shared memory transport. This issue only affected single node scenarios.

Intel® MPI Library 2021 Update 17 - oneAPI 2025.3

  • MPI 5.0 standard technical preview (Linux) (C only, available via "-mpi-abi" compiler wrapper option)
  • Additional P-Core/E-Core recognition and settings for CPU pinning.
    • New options added to I_MPI_PIN_PROCESSOR_EXCLUDE_LIST environment variable to exclude P-Cores / E-Cores (ecore, ecores, pcore, pcores)
  • Integrated changes from libfabric v2.2.0
  • Added implicit mode for Thread Split functionality (Tech preview)
  • Added Fortran modules for gcc-15.1.0, and removed legacy Fortran modules for older GCC versions (4.8-6.1) to streamline compatibility.
  • Added Allreduce CUDA Kernel for efficient GPU data offload
  • Bug fixes

Known Issues and Limitations

  • When using thread split functionality with the new implicit mode, ensure that the application follows the semantics of the MPI_THREAD_SPLIT communication model and set I_MPI_THREAD_MAX=<N> to the number of threads per rank, along with I_MPI_THREAD_SPLIT=1 and I_MPI_THREAD_SPLIT_MODE=implicit.
  • Hang with 2021.6 and earlier on Red Hat Enterprise Linux*.  See https://www.intel.com/content/www/us/en/developer/articles/troubleshooting/mpi-library-hang-with-rhel-8-6.html for details.
  • If vars.sh sourced from another script with no explicit parameters, it will inherit parent script options and may process matching ones. 
  • stdout and stderr redirection may cause problems with LSF's blaunch.
    • verbose option may cause a crash with LSF's blaunch. Please do not use -verbose option or set -bootstrap=ssh.
  • To use shared memory only and avoid network initialization on the single node, please explicitly set I_MPI_FABRICS=shm.

  • Application may hang with LSF job manager in finalization if the number of nodes is more than 16. The workaround is setting -bootstrap=ssh or -branch-count=-1.

  • SLURM* option --cpus-per-task in combination with Hydra option -bootstrap=slurm leads to the incorrect pinning. I_MPI_PIN_RESPECT_CPUSET=disable may fix this issue.

  • Incorrect process pinning with I_MPI_PIN_ORDER=spread. Some of the domains may share common sockets.

  • Nonblocking MPI-IO operations on NFS filesystem may work incorrectly for files larger than 2 GB.
  • Some MPI-IO features may not be working on NFS v3 mounted w/o "lock" flag.

  • MPI-IO operations may work unreliable with NFSv3 on Red Hat* Enterprise Linux*/CentOS* 7.4 and 7.5 due to a bug in OS kernel (version 3.10.0-693.el7.x86_64 and 3.10.0-862.el7.x86_64 respectively).

  • MPI_Comm_spawn on ofi/mlx does not work on non-IA platform. As a workaround ofi/verbs provider on small scale may be used.

  • On hybrid processors with efficient E-cores and performance P-cores, such as 12th and 13th Gen Intel® Core™ processors, Intel® MPI Library might pin processes to E-cores resulting in not best overall performance.  We recommend disabling pinning with I_MPI_PIN=no, or using I_MPI_PIN_PROCESSOR_LIST and/or I_MPI_PIN_PROCESSOR_EXCLUDE_LIST to explicitly set the process pinning.
  • HBW memory policies applied to window segments for RMA operations are not yet supported.
  • To use the cxi provider, set FI_PROVIDER=cxi, and FI_PROVIDER_PATH and I_MPI_OFI_LIBRARY to point to cxi enabled libfabric. On machines with CXI < 2.0, also set FI_UNIVERSE_SIZE=1024 to bypass a CXI bug that causes a crash otherwise. In case you experience hangs when running with the CXI provider, or see messages about Cassini Event Queue overflow, try increasing the FI_CXI_DEFAULT_CQ_SIZE cvar to values ranging from 16384 to 131072. This is a known issue with the CXI provider. When using 4th Generation Intel® Xeon® Scalable Processors nodes in SNC4 mode, the default CPU pinning (and in turn the nic assignment) is not correct for multiples of 6 ranks and the default GPU pinning is not correct for multiples of 8 ranks. In such cases, it is recommended to explicitly specify CPU, GPU, and NIC pinning using cvars.
  • UCX* 1.16.x contains a bug resulting in :
    Caught signal 8 (Floating point exception: floating-point invalid operation)
    The bug is only fixed with commit 1fdcd9f, which is not present in 1.16-rc1. Please make sure to use a version of UCX* that contains the bugfix. 

  • Starting with Slurm* version 23.11, users may encounter an error if the I_MPI_HYDRA_BOOTSTRAP=ssh environment variable is set after node allocation. To address this issue, consider the following workarounds:
    Set I_MPI_HYDRA_BOOTSTRAP=ssh before node allocation. For instance, you can set it in your .bashrc file.
    Set I_MPI_HYDRA_BOOTSTRAP=ssh after node allocation then unset I_MPI_HYDRA_BOOTSTRAP_EXTRA_ARGS.

Removals

Starting from Intel® MPI Library 2019, the deprecated obsolete symbolic links and directory structure have finally been removed. If your application still depends on the old directory structure and file names, you can restore them using the script.

System Requirements

Introduction

This document provides details about hardware, operating system, and software prerequisites for the Intel® MPI Library.

Hardware Requirements

  • Systems based on the Intel® 64 architecture, in particular:
    • Intel® Core™ processor family or higher
    • Intel® Xeon® Scalable processor family
    • Intel® Xeon® 6 processor family
  • 1 GB of RAM per rank (2 GB recommended)
  • 1 GB of free hard disk space

Supported Accelerators 

Integrated GEN9 or higher GPUs including latest Intel® Iris® Xe MAX graphics.
Nvidia* GPUs (minimal tested version is NVIDIA* Tesla P100).

Drivers and Libraries

oneAPI Level Zero API 1.0.
CUDA* Version 11.3 or higher.

Software Requirements

Linux* OS

  • Red Hat* Enterprise Linux* 8, 9, 10
  • SUSE* Linux Enterprise Server* 15 SP5, 15 SP6, 15 SP7
  • Fedora* 41, 42
  • Rocky Linux* 9
  • Amazon* Linux 2023

Compilers

  • GNU*: C, C++, Fortran 77 3.3 or newer, Fortran 95 4.8.0 or newer
  • Intel® C++/Fortran Compiler 17.0 or newer

Debuggers

  • Rogue Wave* Software TotalView* 6.8 or newer
  • Allinea* DDT* 1.9.2 or newer
  • GNU* Debuggers 7.4 or newer

Batch Systems

  • Platform* LSF* 6.1 or newer
  • Altair* PBS Pro* 7.1 or newer
  • Torque* 1.2.0 or newer
  • Parallelnavi* NQS* V2.0L10 or newer
  • NetBatch* v6.x or newer
  • SLURM* 1.2.21 or newer
  • Univa* Grid Engine* 6.1 or newer
  • IBM* LoadLeveler* 4.1.1.5 or newer
  • Platform* Lava* 1.0

Fabric Software

Supported Languages

  • For GNU* compilers: C, C++, Fortran 
  • For Intel® compilers: C, C++, Fortran 

Clustered File Systems

  • IBM Spectrum Scale* (GPFS*)
  • LustreFS*
  • PanFS*
  • NFS* v3 or newer

Linux General Purpose Intel® GPUs (GPGPU) Driver:

For all Intel® GPUs, see this article, https://dgpu-docs.intel.com/, and follow the directions for your device.

 

Notices and disclaimers

As announced previously, Windows driver support of integrated graphics processors included with 6th - 10th Gen Intel® Core™ Processor and related Intel® Atom®, Pentium®, and Celeron® processors is deprecated and has moved to maintenance mode. Only security and critical bug fixes will be updated.

oneAPI tools using existing integrated graphics processor functionality in the aforementioned processors may continue to work, but will no longer be supported. Note that CPU functionality for these processors remains fully supported and unaffected.

Intel technologies may require enabled hardware, software or service activation.

No product or component can be absolutely secure.

Your costs and results may vary.

© Intel Corporation. Intel, the Intel logo, and other Intel marks are trademarks of Intel Corporation or its subsidiaries. Other names and brands may be claimed as the property of others.

No license (express or implied, by estoppel or otherwise) to any intellectual property rights is granted by this document.

The products described may contain design defects or errors known as errata which may cause the product to deviate from published specifications. Current characterized errata are available on request.

Intel disclaims all express and implied warranties, including without limitation, the implied warranties of merchantability, fitness for a particular purpose, and non-infringement, as well as any warranty arising from course of performance, course of dealing, or usage in trade.

Legal Information

Intel® technologies may require enabled hardware, software or service activation.

No product or component can be absolutely secure.

Your costs and results may vary.

© Intel Corporation. Intel, the Intel logo, and other Intel marks are trademarks of Intel Corporation or its subsidiaries. Other names and brands may be claimed as the property of others.

No license (express or implied, by estoppel or otherwise) to any intellectual property rights is granted by this document.

The products described may contain design defects or errors known as errata which may cause the product to deviate from published specifications. Current characterized errata are available on request.

Intel disclaims all express and implied warranties, including without limitation, the implied warranties of merchantability, fitness for a particular purpose, and non-infringement, as well as any warranty arising from course of performance, course of dealing, or usage in trade.

Technical Support

Every purchase of an Intel® Software Development Product includes a year of support services, which provides Priority Support at our Online Service Center web site.

In order to get support you need to register your product in the Intel® Registration Center. If your product is not registered, you will not receive Priority Support.

Additional Resources

Intel® MPI Library

 

 

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Product and Performance Information

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Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.