You can set up Incremental Synthesis with a project in the Synthesis page of the Settings dialog box.
X-Ref Target - Figure 1-16
Note the following important settings:
•Incremental Synthesis selection box: Use the Browse button to indicate if incremental synthesis uses a known checkpoint, the last checkpoint created (default), or if incremental synthesis is disabled.
°incremental_mode Synth Design option: This describes how aggressive synthesis will be with optimizations across partitions. The values are quick, default, aggressive, and off. Quick turns off most optimizations, and aggressive will turn on more and repeat synthesis on certain sections. Off will tell synthesis not to use the incremental synthesis information in the DCP file.