[MITgcm-devel] new r4 SingleCpuIO efficiency

[Dimitris Menemenlis]

Jean-Michel, I was trying to recover an old test experiment on the  
cs32 grid
with blank tiles and I get some errors of type:

(PID.TID 0000.0001) *** ERROR *** EXCH2_CHECK_DEPTHS: tile #    13  
(bi,bj=  13,   1 ):
(PID.TID 0000.0001) *** ERROR *** W.Edge has    1 unconnected points  
with non-zero depth.

etc., and the program aborts.

If I comment exch2_check_depths, the code will run OK and it will  
produce hFacW.data,
hFacS.data, hFacC.data, and Depth.data output files that are exactly  
identical to those
obtained without blank tiles, so I am pretty sure that blank tiles are  
chosen and specified correctly.

Is there a requirement that halos of blank tiles also be land points?
Or is there a restriction pertaining to OLx/Oly compared to sNx/sNy?

===

A separate, possibly related issue, integrating a cs32 experiment with  
different tile configurations, I get substantial differences in ETAN  
after 72 time steps, especially when OLy<=sNy.
For example,
24-tile vs 12-tile setup: difference is < real*4 precision of output  
files
176-tile vs 192-tile: up to 4e-6 m difference
176-tile vs 12-tile: up to 4e-2 cm difference

Is there some restriction pertaining to OLx/Oly compared to sNx/sNy in  
order for the
solver to be accurate?

===

If helpful, the test set-up that I am experimenting with is documented  
in
the first two experiments described in
MITgcm_contrib/high_res_cube/README.cs32

D.

On May 22, 2009, at 11:09 AM, Jean-Michel Campin wrote:

> If you are not using blank-tiles, then you just need to remove
> our local copy of w2_e2setup.F & W2_EXCH2_TOPOLOGY.h
> With blank-tiles, you remove also thoses 2 files but you need
> a "data.exch2" parameter file (with the list of blank-tiles),
> and could find one example (with blank-tiles) here:
> MITgcm/verification/adjustment.cs-32x32x1/input/data.exch2.mpi
> (the .mpi suffix is just there for MPI testing purpose).
> If this does not work, you should complain.