3.2 Optimizing the performance

   

NPROMA

:

Definition

: working length of the model data rows. Refer to appendix A.5.2 for more information.

Scope

: positive or negative integer but not zero nor a power of 2, and limited (in absolute value) to the biggest helpful value (ie : the number of model gridpoints in the current processor). When it is negative the absolute value is used ; when it is positive the program will try to increase it in the limit of 10 % in an attempt to improve even more the optimization.

Default value

: if LECMWF=.TRUE. then NPROMA=2047, else NPROMA=67.

Namelist location

: NAMDIM

   

NFPROMAG

:

Definition

: working length of the post-processing data rows. Refer to appendix A.5.2 for more information.

Scope

: positive integer but not zero nor a power of 2, and limited to the biggest helpful value (ie : the number of post-processing gridpoints in the current processor).

Default value

: internally computed as the mean of the helpful values gathered among all processors.

Namelist location

: NAMFPSC2

   

NFPROMEL

:

Definition

: working length of the post-processed extension zone data rows. Refer to appendix A.5.2 for more information.

Scope

: positive integer but not zero nor a power of 2, and limited to the biggest helpful value (ie : the number of gridpoints in the post-processed extension zone of the current processor).

Default value

: internally computed as the biggest helpful value.

Namelist location

: NAMFPEZO

   

NPROC

:

Definition

: Number of processors used for the distribution per nodes.

Scope

: Integer between 1 and the maximum number of processors of the machine.

Default value

: 0 (So this parameter must be set explicitely !)

Namelist location

: NAMPAR0

     

LMPOFF

:

Definition

: Control of message passing libraries. Set LMPOFF=.TRUE. to avoid entering message passing subroutines when NPROC=1.

Scope

: Boolean.

Default value

: .FALSE.

Namelist location

: NAMPAR0

       

NPRTRW, NPRTRV

:

Definition

: Numbers of processors used respectively for the waves distribution and the vertical distribution in spectral space.

Scope

: Integers greater than zero and so that NPRTRW*NPRTRV=NPROC. For the time being the vertical distribution is not working, so (NPRTRW,NPRTRV) must be (NPROC,1).

Default value

: 0 (So these parameters must be set explicitely !)

Namelist location

: NAMPAR0

         

NPRGPNS, NPRGPEW

:

Definition

: Numbers of processors used respectively for the North-South and East-West gridpoint distributions.

Scope

: Integers greater than zero and so that NPRGPNS*NPRGPEW=NPROC.
For the time being the East-West distribution is not working in ARPEGE/ALADIN, so (NPRGPNS,NPRGPEW) must be (NPROC,1).

Default value

: 0 (So these parameters must be set explicitely !)

Namelist location

: NAMPAR0

             

NSTRIN, NSTROUT

:

Definition

: Numbers of processors used respectively for unpacking input data from file and for packing output data to file.

Scope

: Integers between 1 and NPROC. The best performance in ARPEGE/ALADIN is obtained with NSTRIN=NPROC and NSTROUT$\approx$NPROC/2.

Default value

: if LECMWF=.TRUE. then (NSTRIN,NSTROUT)=(1,0).
Else (NSTRIN,NSTROUT)=(NPROC,1).

Namelist location

: NAMPAR1

     

NSTREFP

:

Definition

: Number of processors used for the distribution of the post-processed extension zone (for LAM outputs only).

Scope

: Integer between 1 and NPROC.

Default value

: 1

Namelist location

: NAMFPEZO

   

LSPLIT

:

Definition

: Control of latitude row splitting. set LSPLIT=.TRUE. to improve the balance of distribution.

Scope

: Boolean. This option does not work in ALADIN (LSPLIT must be .FALSE.).

Default value

: .TRUE.

Namelist location

: NAMPAR1

   

NFPXFLD

:

Definition

: Chunk size of global fields while gathering the post-processed distributed fields before writing out to output files. Refer to appendix A.5.1 for more information.

Scope

: Integer greater than zero and limited to the biggest helpful value (ie : the number of post-processed fields).

Default value

: internally computed as the biggest helpful value.

Namelist location

: NAMFPIOS