18.3.8. Run Control Parameters

Parallel and Partitioner Control

parallel optimization level

Type

Integer

Default Value

0

Description

This parameter applies pre-set optimizations to improve parallel performance. Increasing the value of this parameter will increase the expected performance gain, but it may also reduce robustness in some cases. Other expert parameters are available to control individual performance optimizations.

part adjacency output

Type

Logical

Default Value

f

Description

This parameter controls whether the partition adjacency data is stored in the .par file.

part mmesh intersect option

Type

Integer

Default Value

0

Description

This parameter can be used to enable a modified algorithm for partitioning moving mesh cases. The modified algorithm recognizes moving domain interfaces. A value of 1 selects the newer algorithm. A value of 0 selects the original algorithm.

The modified algorithm aims to keep both sides of a GGI interface within the same partition, potentially improving convergence behavior in parallel and reducing communication requirements between partitions.

This expert parameter affects parallel runs only; it has no effect on serial runs.

rad data in par file

Type

Logical

Default Value

f

Description

This parameter controls whether the radiation mesh is stored in the .par file.

Performance

cache optimization level

Type

Integer

Default Value

1

Description

Controls the default value of various other parameters that influence cache memory usage. Performance effects might vary and are likely to be both case and hardware dependent.

1 = No cache optimization (default).

2 = Unlimited number of internal mesh element groups (instead of a limit of 256).

3 = Option 2 plus use a reduced internal mesh element group size (lower than the default of 3000).

4 = Option 3 plus use Cuthill-McKee mesh vertex ordering in the linear solver.

Licensing

reserve solver licenses

Type

Logical

Default Value

T

Description

This parameter causes preliminary tools, such as the partitioner, to reserve the required solver licenses for any following solver runs, helping to avoid a license availability issue after having invested time in running a preliminary tool.

Note that this parameter has no effect when running the solver in Partition Only mode because there is no subsequent solver step that would require a license.

Note also that the parameter (when set to "T") attempts to provide, but does not guarantee, license availability; it is unlikely but possible that an unrelated solver process will use one of the required licenses in the small window of time after the preliminary tools have run but before the solver has started.