[MITgcm-support] changing the number of tiles

[Ed Hill]

On Wed, 2006-03-01 at 11:47 -0800, Paola Cessi wrote:
> Is it possible to restart a computation with 4*N tiles, using the pickup 
> files generated with N tiles, while keeping Nx and Ny fixed? In other 
> words, is it possible to change nPx and nPy in a restart run, while 
> keeping Nx and Ny the same? (without using netcdf)

Hi Paola,

Yes.  As long as Nx and Ny remain constant, you can vary the sNx,nSx,nPx
and sNy,nSy,nPy quantities.

Also, there are a few wrinkles:

 - the numbers have to remain integers!

 - if you're using cube-sphere grids then you may need to generate 
   new exch2 topology files in order to increase the number of tiles 
   so that you can use more processors

 - if you're using the zonal filter package then you can't cut the
   domain in the X direction since the ffts can't be spatially 
   truncated

Ed

-- 
Edward H. Hill III, PhD
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