Performance can be improved for Blockset sort applications by using Dynamic Storage Adjustment (DSA).

The DSA parameter sets the maximum amount of storage available to DFSORT for dynamic storage adjustment of a Blockset sort application when SIZE/MAINSIZE=MAX is in effect. If you specify a DSA value greater than the TMAXLIM value, you allow DFSORT to use more storage than the TMAXLIM value if doing so should improve performance. DFSORT only tries to obtain as much storage as needed to improve performance up to the DSA value.