[MITgcm-support] Poor cpu usage percentage

[Rogan, Nicholas]

Unfortunately, I'm only a "temp" here at GEOMAR so don't have access to any of the high performance equipment. I am unsurprisingly looking forward to getting a more long-term position and the support that comes with it.

N

On 20/07/15 09:55 PM, Ryan Abernathey  <ryan.abernathey at gmail.com> wrote:
> 
> 
> 
> Nick,
> 
> I would humbly suggest that it is a waste of time to optimize MITgcm for a six year old laptop. Surely at Geomar you have more powerful computing resources available to you, for which MITgcm is well tested and optimized...
> 
> Best,
> Ryan
> 
> 
> 
> On Mon, Jul 20, 2015 at 10:47 AM, Rogan, Nicholas <nrogan at geomar.de> wrote:
> 
> > hi Dimitris,
> > 
> > Thanks for your patience! 
> > 
> > It appears that it is a problem with the I/O routines as there are significant differences in wall clocl times between the two compilations. 
> > 
> > The main routines that are time expensive are 
> > LOAD_FIELDS_DRIVER
> > >> EXF_GETFORCING 1500s vs 300s
> > 
> > MONITOR 1700s vs 300s 
> > 
> > and 
> > 
> >  DO_THE_MODEL_IO 1900s vs 1200s
> > 
> > There aren't really any other major differences, in fact on the whole the users and system times for the iMac are less than those for the macbook.
> > 
> > Looking at the Makefiles there are the following differences:
> > iMac
> > - Does not have a specified F90C compiler (The macbook pro has gfortran specified as F90C compiler)
> >  NB The other compilers are identical between the two compilations, i.e. FC=gfortran, CC=gcc, LINK=gfortran
> > 
> > FFLAGS (relative to macbook)
> > - Does not have: -Wunused
> > - Does have : -f-no-second-underscore -fbacktrace
> > - BOTH HAVE: -Wunitialized -fconvert=big-endian
> > 
> > FOPTIM
> > - Does not have: -ftree-vectorize
> > 
> > NOOPTFLAGS
> > - Does not have: -O2 -funroll-loops
> > - Does have : -O0
> > 
> > LIBS
> > - Does not have: -lcurl
> > 
> > There are also a lot of included .h files that occur in the MacBook's Makefile that are absent from the iMac.
> > 
> > Any quick suggestions? I'll keep work myself on trying to figure out the implications of the differences.
> > 
> > Thanks!
> > 
> > Nick
> > 
> > 
> > 
> > On 20/07/15 03:02 PM, Dimitris Menemenlis  <dmenemenlis at gmail.com> wrote:
> > > 
> > > 
> > > 
> > > 
> > > 
> > > you mainly need to look at your fortran and c compilers and compiler options.
> > > 
> > > 
> > > 
> > > > 
> > > > On Jul 20, 2015, at 9:29 AM, Rogan, Nicholas <nrogan at geomar.de> wrote:
> > > > 
> > > > I'm comparing the two Makefiles now, so far only different Netcdf/compiler locations.
> > > > 
> > > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > -- 
> > Kind regards,
> > 
> > Nick
> > 
> > ------------------------------------------------------
> > Dr Nicholas Rogan
> > Postdoctoral Researcher
> > http://www.geomar.de/en/mitarbeiter/fb2/ch/nrogan/
> > 
> > GEOMAR Helmholtz Centre for Ocean Research, Kiel
> > Wischhofstraße 1-3, Build. 12
> > D-24148 Kiel
> > Germany
> > ------------------------------------------------------
> > 
> > 
> > _______________________________________________
> > MITgcm-support mailing list
> > MITgcm-support at mitgcm.org
> > http://mitgcm.org/mailman/listinfo/mitgcm-support
> > 
> > 
> 
> 
> 
> 
-- 
Kind regards,

Nick

------------------------------------------------------
Dr Nicholas Rogan
Postdoctoral Researcher
http://www.geomar.de/en/mitarbeiter/fb2/ch/nrogan/

GEOMAR Helmholtz Centre for Ocean Research, Kiel
Wischhofstraße 1-3, Build. 12
D-24148 Kiel
Germany
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