To set these advanced options during Layout, click Advanced in the Layout dialog box.
Setting this option to values within a recommended range of 1-4 changes the weight of the timing objective function, thus influencing the results of timing-driven place-and-route in favor of either routability or performance.
Value 4 (default) puts maximum emphasis on the performance; value 1 shifts priority to routability, but still evaluates timing goals during layout.
In general, the performance of a non-congested design increases with a higher timing weight setting. In highly congested designs the performance improves with lower timing weight settings because of better routability. Use intermediate values to balance the performance-routability tradeoff for your design.
For designs that are very congested, you may want to put even more emphasis to the routability than level 1 provides. In this case try running standard-mode placer, followed by the timing-driven router. If this is insufficient, run both place-and-route in standard mode.
Note: If you change the Timing Weight you must re-run the placer to complete routing. Changing the Timing Weight has no effect if you do not re-run the placer.
Click Restore Defaults to run the factory default settings for advanced options.