impdp performance in 11.1 vs 11.2

I was wondering if someone might know off the top of their head why I am seeing such a dramatic difference in runtimes for impdp tests between 11.1.0.7 and 11.2.0.4 versions

I run the following for impdp.
impdp directory=migrate_dir SCHEMAS=X,Y,Z,A,B,C,D dumpfile=exp_TSTR_%U.dmp PARALLEL=4

The above impdp takes about 3 hours when the database is 11.1.0.7. I upgrade the database to 11.2.0.4 with dbua and the import takes about 1hr10mins. No other changes made besides the upgrade, unless dbua changed something that I am not aware of right away. I restored the database back to 11.1.0.7 just to confirm it takes 3 hours.

I haven't really checked what is going on in the database during the import since I don't have all my access in place yet. Was wondering if someone might know of the top of their head. Seems like the 11.1.0.7 impdp gets held down during the index builds

Thanks,
Mike

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