Quartus® Prime Standard Edition User Guide: Design Compilation

ID 683283
Date 10/22/2021
Document Table of Contents Resource Utilization

There are possible timing performance utilization effects due to partitioning and creating a floorplan. Not all designs encounter these issues, but you should consider these effects if a flat version of your design is very close to meeting its timing requirements, or is close to using all the device resources, before adding partition or floorplan assignments:
  • Partitions can increase resource utilization due to cross-boundary optimization limitations if the design does not follow partitioning guidelines. Floorplan assignments can also increase resource utilization because regions can lead to unused logic. If your device is full with the flat version of your design, you can focus on creating partitions and floorplan assignments for timing-critical or 
often-changing blocks to benefit most from incremental compilation.
  • Partitions and floorplan assignments might increase routing utilization compared to a flat design. If long compilation times are due to routing congestion, you might not be able to use the incremental flow to reduce compilation time. Review the Fitter messages to check how much time is spent during routing optimizations to determine the percentage of routing utilization. When routing is difficult, you can use incremental compilation to lock the routing for routing-critical blocks only (with other partitions empty), and then compile the rest of the design after the critical blocks meets their requirements.
  • Partitions can reduce timing performance in some cases because of the optimization and resource effects described above, causing longer logic delays. Floorplan assignments restrict logic placement, which can make it more difficult for the Fitter to meet timing requirements. Use the guidelines in this manual to reduce any effect on your design performance.