In one of the SORT job we are making use of HIPRMAX=OPTIMAL. I have looked at about it here:
z/OS DFSORT Application Programming Guide
Blockset sorting performance can be improved by using Hiperspace along with disk for temporary storage.
The HIPRMAX parameter sets the maximum amount of Hiperspace to be used during a run. Specifying HIPRMAX=OPTIMAL allows DFSORT to optimize the maximum amount of Hiperspace to be used during a run, subject to other system and concurrent Hipersorting, memory object sorting and dataspace sorting activity throughout the run. Total Hipersorting activity on a system can be further limited by the EXPMAX, EXPOLD, and EXPRES installation options. See the description of HIPRMAX in OPTION control statement for more information.
But what kind of application would really need a mention about HIPRMAX? What exactly the use of it?