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Cray libraries

For the Cray libraries that are available as a modules prefixed by cray-, the compiler wrappers will automatically take care of adding the search paths for the include files and the libraries and provide the linker with the appropriate options. This means that, as a user, you don't need to provide such information to cray-libsci, cray-fftw, cray-hdf5, and cray-netcdf.


module load cray-libsci man intro_libsci

Cray LibSci is a collection of numerical routines tuned for performance on Cray systems. Most users, for most codes, will find that they obtain better performance by using Cray LibSci routines in their applications instead of using public domain or user‐written versions.

The general components of Cray LibSci are:

  • BLAS: Basic Linear Algebra Subroutines
  • CBLAS: C interface to the legacy BLAS
  • BLACS: Basic Linear Algebra Communication Subprograms
  • LAPACK: Linear Algebra routines
  • ScaLAPACK: parallel Linear Algebra routines

Two libraries unique to Cray are:

  • IRT: Iterative Refinement Toolkit, a library of solvers and tools that provides solutions to linear systems using single‐precision factorizations while preserving accuracy through mixed‐precision iterative refinement.

  • CrayBLAS: a library of BLAS routines auto-tuned for Cray EX series systems through extensive optimization and runtime adaptation.

Multithreaded version

The OpenMP libraries will be linked in when the OpenMP compiler flag is set.


module load cray-fftw man intro_fftw3

FFTW is a C subroutine library with Fortran interfaces for computing complex-to-complex, real-to-complex, complex-to-real, and real-to-real single and multidimensional discrete Fourier transforms (DFTs). The library also includes routines to compute discrete cosine and sine transforms (DCTs/DSTs) on even and odd data, respectively.

Multithreaded version

The OpenMP libraries will be linked in when the OpenMP compiler flag is set.

Official documentation


module load cray-hdf5 | module load cray-hdf5-parallel

HDF5 is a data model, library, and file format for storing and managing data. It supports a variety of data types, and is designed for flexible and efficient I/O and for high volume and complex data. HDF5 is portable and is extensible, allowing applications to evolve in their use of HDF5. The HDF5 Technology suite includes tools and applications for managing, manipulating, viewing, and analyzing data in the HDF5 format.

Official documentation


module load cray-netcdf | module load cray-parallel-netcdf man netcdf

NetCDF (network Common Data Form) is a set of interfaces for array-oriented data access and a freely distributed collection of data access libraries for C, Fortran, C++, Java, and other languages. The netCDF libraries support a machine-independent format for representing scientific data. Together, the interfaces, libraries, and format support the creation, access, and sharing of scientific data.

Official documentation


module load cray-netcdf-hdf5parallel

A serial NetCDF built against parallel HDF5.