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Math libraries on Ookami

There are multiple math libraries available on Ookami, listed below. 

LAPACK: Linear algebra package


BLAS: Basic linear algebra subprograms


ScaLAPACK: Scalable linear algebra package


FFTW: Fastest Fourier Transform in the West


The specific implementation of these libraries on Ookami will depend on which compiler you are using.


Cray LibSci

Cray users can take advantage of the LibSci library to access versions of BLAS, LAPACK,  and SCALAPACK that have been optimized for Cray systems.

To access these libraries on Ookami, please load the following module:

module load CPE

This will load several Cray modules, including the cray-libsci/ module.

To additionally make a Cray version of FFTW available, please load the following module (after loading CPE):

module load cray-fftw/


Fujitsu SSL2 Library

The Fujitsu SSL2 library is Fujitsu's implementation of BLAS, LAPACK, and SCALAPACK.  The SSL2 library is automatically available when the Fujitsu compiler module is loaded:

module load fujitsu/compiler/4.8

In addition, an implementation of FFTW compiled with the Fujitsu compilers and using SVE is available via the following module:

module load fftw3/fujitsu/sve-1.1.0


Arm Performance Libraries

The Arm Performance Libraries provide optimized versions of BLAS, LAPACK and FFTW.  To access these libraries, please do the following:

module load arm-modules/22.1
module load armpl/22.1.0

Because Arm does not provide an MPI implementation, we have built our own version of SCALAPACK using the Arm compilers and performance libraries along with OpenMPI.  To access it, please load the following module:

module load scalapack/arm22/2.2.0



OpenBLAS is an optimized and SVE-enabled version of the BLAS library available on Ookami.  To access a recent version of OpenBLAS compiled with the latest GCC, please do:

module load openblas/gcc13/0.3.21