How to understand why Merge/Purge Plus (MPP) 6.4.3 job runs 2 or 3 times fast than MPP 6.6.0 job on the Windows platform

Operating System: Windows


An example of 1 job run on each version:
MPP 6.6.0 -  took 28 minutes
MPP 6.4.3 -  took   8 minutes -  3.5 times faster

In the MPP 6.6.0 release with a new AcuCobol compiler and updated software to perform better duplicate elimination, there are now more instructions in the MPP 6.6.0 software. With more instructions per each attempt for a duplicate elimination, the job will take longer.
UPDATED:  August 11, 2017