We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome, Firefox, Internet Explorer 11, Safari. Thank you!

AR# 17684

6.1i PAR - The Effort Level option has been changed for version 6.1i


Keywords: increased, runtime, run time, PAR, effort, level, -ol, new

Urgency: Standard

General Description:
The 6.1i PAR effort level option (-ol) has changed from five levels (1-5) to three (std, med, high). How do the new effort levels compare to the old ones?


Effort level "std" in 6.1i is comparable to effort level "2" in 5.2i. It is recommended that this effort be used unless it becomes apparent that the design requires a higher effort level to meet timing.

Effort level "medium" has proven to yield comparable performance and run time results to 5.2i effort level 5 for many designs. This level is recommended for designs that are close to meeting timing at level "std", but require a higher effort level to reach timing closure.

Effort level "high" can achieve better results compared with 5.2i effort level 5 in many designs but at the cost of additional runtime in Placement and Routing. This effort level is recommended for designs where the most aggressive approach is needed to reach timing closure or for cases where the designer wants to evaluate the best case timing results for the design.

NOTE: For script and command line users, effort levels 1-5 are still accepted in the 6.1i software. They are then translated to the new levels as follows; 1 and 2 => "std", 3, 4 and 5 => "med". The extra effort level switch (-xe) will have an effect only if the switch "-ol high" is also used. It no longer has an effect when "-ol 5" is used.
AR# 17684
Date Created 09/03/2007
Last Updated 10/23/2008
Status Archive
Type General Article