How do I get identical results from compilations in the Quartus Prime software? - How do I get identical results from compilations in the Quartus Prime software? Description To get identical results from compilations in the Quartus® Prime software the following items must be identical for each compilation: All design source files including Synopsys Design Constraints ( .sdc ) files Note that changes to comments or naming may cause different compilation results. All Quartus Prime project settings The version of the Quartus Prime software including patches The portion of the design that is preserved with the Rapid recompile option or with incremental compilation partitions Note that the db and incremental_db directories must be identical from compilation to compilation to ensure identical results. For example, the first compilation after turning on a preservation option may have different results than the previous compilation for portions of the design that are not preserved. Subsequent compilations with no changes will be identical. Operating system and CPU For example, compiling on Windows OS may give different results than compiling on Linux OS Compiling using the 32-bit version of the Quartus II software may give different results than compiling using the 64-bit version. Different CPU architectures can have different floating-point implementations. Additionally, if you are using the SignalTap™ II Logic Analyzer, you must select nodes using the SignalTap II: pre-synthesis filter to ensure identical results. If any of these items are changed, the Fitter starts with a different initial placement for its fitting algorithms that can give different compilation results, programming files and project checksum. Note: If only Operating System and/or CPUs changes, seed noise will be seen but results will be of similar QOR. Related Articles Why don't I get identical fitter results when my source files haven't changed? Why do I see different fitting and timing results when I recompile my design in the Quartus II software version 12.0 SP2 and earlier? Custom Fields values: ['novalue'] Troubleshooting novalue False ['novalue'] ['FPGA Dev Tools Quartus® Prime Software Pro', 'FPGA Dev Tools Quartus II Software'] novalue novalue ['Programmable Logic Devices'] ['novalue'] ['novalue'] ['novalue']