Introduction

The 2DECOMP&FFT library is a software framework in Fortran to build large-scale parallel applications. It is designed for applications using three-dimensional structured mesh and spatially implicit numerical algorithms. At the foundation it implements a general-purpose 2D pencil decomposition for data distribution on distributed-memory platforms. On top it provides a highly scalable and efficient interface to perform three-dimensional distributed FFTs. The library is optimised for supercomputers and scales well to hundreds of thousands of cores. It relies on MPI but provides a user-friendly programming interface that hides communication details from application developers.

Download

The latest version is 1.5.847, available from the Download page.

Features

Here is a list of 2DECOMP&FFT's main features:

• General-purpose 2D pencil decomposition module to support building large-scale parallel applications on distributed memory systems.
• Highly scalable and efficient distributed Fast Fourier Transform module, supporting three dimensional FFTs (both complex-to-complex and real-to-complex/complex-to-real).
• Halo-cell support allowing explicit message passing between neighbouring blocks.
• Parallel I/O module to support the handling of large data sets.
• Shared-memory optimisation on the communication code for multi-code systems.
• Interface with most popular external FFT libraries.

2DECOMP&FFT is designed to be:

• Scalable - The library and applications built upon it are known to scale to o(10^5) cores on major supercomputers.
• Flexible - Software framework to support building higher-level libraries and many types of applications.
• User-friendly - Black-box implementation and very clean application programming interface hiding most communication details from applications.
• Portable - Code tested on major hardware architectures, including Cray XT/XE, IBM Blue Gene and many others.

Publication

If you wish to cite this work, you are recommended to use the following paper:

• N. Li and S. Laizet, "2DECOMP&FFT – A highly scalable 2D decomposition library and FFT interface", Cray User Group 2010 conference, Edinburgh, 2010. Download PDF

Acknowledgements

This software is derived from several projects funded under the HECToR Distributed Computational Science and Engineering (CSE) Service operated by NAG Ltd. HECToR - A Research Councils UK High End Computing Service - is the UK's national supercomputing service, managed by EPSRC on behalf of the participating Research Councils. Its mission is to support capability science and engineering in UK academia. The HECToR supercomputers are managed by UoE HPCx Ltd and the CSE Support Service is provided by NAG Ltd.