The

MKL_NUM_STRIPES

environment variable controls the

Intel® oneAPI Math Kernel Library

threading algorithm for

?gemm

functions. When

MKL_NUM_STRIPES

is set to a positive integer value

nstripes

,

Intel® oneAPI Math Kernel Library

tries to use a number of partitions equal to

nstripes

along the leading dimension of the output matrix.

The following table explains how the value

nstripes

of

MKL_NUM_STRIPES

defines the partitioning algorithm used by

Intel® oneAPI Math Kernel Library

for

?gemm

output matrix;

max_threads_for_mkl

denotes the maximum number of OpenMP threads for

Intel® oneAPI Math Kernel Library

:

The following figure shows the partitioning of an output matrix for

nstripes

= 4 and a total number of 8 OpenMP threads for column-major and row-major orderings:

You can use support functions

mkl_set_num_stripes

and

mkl_get_num_stripes

to set and query the number of stripes, respectively.