Quartus Partition Post Fit preservation

[Altera_Forum]

Hello all, 

 Quartus preserve post fit of over 80% of my design but compilation time.. is like a new compilation from scratch.. (1:30h)  Info (171004): Fitter is performing a Standard Fit compilation using maximum Fitter effort to optimize design performance Info (171122): Fitter is preserving placement for 83.83 percent of the design from 3 Post-Fit partition(s) and 0 imported partition(s) of 6 total partition(s)  There is something wrong with Quartus fitter in latest version (15.1)?  Thanks

[Altera_Forum]

I've seen similar behavior on few designs and different Quartus versions. Quartus uses disproportionate amount of time in the preservation and partition merging stages. It takes less time doing build from scratch than using partition (designs that take 30min - 2.5hrs to build)

[Altera_Forum]

Analysis & Synthesis take less time (2 min instead of 10 min) 

Partition Merge take 1-2 min Fitter take 1:09h Timequest 4:20min EDA Writer 1:35m  Problem is fitter.. maybe can't fit using preserved partitions and refit-again? I don't use LogicLock.