[Mitgcm-support] [Fwd: Re: configuring the MITgcm]

[mitgcm-support at dev.mitgcm.org]

Chris,

Your domain....?

A.


-------- Original Message --------
From: "amy" <amy18 at sprynet.com>
Subject: Re: configuring the MITgcm
To: "Alistair Adcroft" <adcroft at mit.edu>
CC: "Amy Solomon" <amy at musashimaru.soest.hawaii.edu>

Hi Alistair,

Yes, I have been following the work that you have been doing on the web.
It really looks great.  I have already started using your subroutine and
parameter index.

I downloaded the man pages last week and figured out how to run
the model on multiple processors. On an SGI Origin 2000 it takes about a
minute per
day to run the model for nPy>7. That seems really slow, doesn't it?
I changed:
nPy=8
sNy=8
define ALLOW_USE_MPI
define ALWAYS_USE_MPI.
What is the difference between those two options?

Most of the time is spent in the cg2d subroutine (I figured out that the
zonal filter doesn't work when  nPx>1 so I have only been varying nPy). The
documentation says that
this routine runs faster when you use interleaving threads. I figured out
how to get more than
one thread running but the model won't run when I use this option.

The atmospheric physics documentation says that a T21 model configuration
takes 1 sec
to run 1 model day on a C90. What do you think the best model performance on
an O2000 would be?

Thank you for your help, Alistair!
Amy