FSANumberOfSubkernels is an option for
FSAPrepareMathematicaScripts and other functions of the
FIESTA interface.
It specifies the value of the NumberOfSubkernels option
to be passed to the FIESTA package when evaluating an integral. The
default value is 4 meaning that 4 parallel kernels will be
used during the computation.
Overview, FSAPrepareMathematicaScripts.