Because placement typically has the greatest impact on overall design performance, the Placer has the most directives of all commands. The following table shows which directives might benefit which types of designs.
| Directive | Designs Benefited |
|---|---|
BlockPlacement
|
Designs with many block RAM, DSP blocks, or both |
ExtraNetDelay
|
Designs that anticipate many long-distance net connections and nets that fan out to many different modules |
SpreadLogic
|
Designs with very high connectivity that tend to create congestion |
ExtraPostPlacementOpt
|
All design types |
SSI
|
SSI designs that might benefit from different styles of partitioning to relieve congestion or improve timing. |