Re: [ESPResSo] Espresso performance with gcc 4.3

[Mehmet Sayar]

Hi Christoph,

Thanks for the quick reply.

I used the default settings. Now I tried your suggestion, but did not change the 
results much. It even made the timing a bit worse :)

You can see the compiler settings I used originally and the timing result below.
I also attached the compiler settings output generated by the trial with your 
suggested options.

Best,

Mehmet

Compiler settings:
------------------
MPI                     = fake
compiler                = gcc
linker                  = gcc
c compiler flags	= -finline-limit=1000000 -fomit-frame-pointer -funroll-loops 
-floop-optimize -ffast-math -Wall -Wno-unused-function -O3 -malign-double -msse2 
-mfpmath=sse -m64
c preprocessor flags    =
linker flags            =
libraries               = -lfftw3  -ltcl8.5  -lm
using debug flags       = no
using profiling flags   = no
inline                  =

Libraries:
----------
Tcl version             = tcl8.5
Tk version              = none
FFTW version            = 3
efence                  = no

Other settings:
---------------
using Espresso chooser  = yes
local config header     = myconfig.h
installation prefix     = /home/msayar/Espresso
pdflatex                = no
makeindex               = no
bibtex                  = no
doxygen                 = no

real    0m41.590s
user    0m40.767s
sys     0m0.552s




Compiler settings:
------------------
MPI                     = fake
compiler                = gcc
linker                  = gcc
c compiler flags        = -march=native -O2 -pipe -fomit-frame-pointer
c preprocessor flags    =
linker flags            =
libraries               = -lfftw3  -ltcl8.5  -lm
using debug flags       = no
using profiling flags   = no
inline                  =

Libraries:
----------
Tcl version             = tcl8.5
Tk version              = none
FFTW version            = 3
efence                  = no

Other settings:
---------------
using Espresso chooser  = yes
local config header     = myconfig.h
installation prefix     = /home/msayar/Espresso
pdflatex                = no
makeindex               = no
bibtex                  = no
doxygen                 = no

real    0m42.635s
user    0m41.923s
sys     0m0.488s

Christoph Junghans wrote:
> Hi Mehmet,
>
> what are the optimizations flags at the end of configure?
>
> My experience with gcc-4.3 in general was that it performs best with
> CFLAGS="-march=native -O2 -pipe -fomit-frame-pointer".
>
> Try
>
> ./configure --with-mpi=fake --disable-processor-optimization \ 
> CFLAGS="-march=native -O2 -pipe -fomit-frame-pointer"
>
> with Espresso.
>
> Cheers,
>
> Christoph
>
> Am 17.08.2009 12:57, schrieb Mehmet Sayar:
> > Hi everybody,
> >
> > I am having some trouble with performance of Espresso which is compiled
> > with gcc 4.3. At least that is my best guess regarding the origin of the
> > problem.
> >
> > I have a couple of 8-core machines with Suse 10.2 installed. I recently
> > updated one of them to Suse 11.1. The machines have exactly the same
> > architecture.
> > Under Suse 11.1 Espresso's performance is more than 10 times slower.
> >
> > Gromacs displays the same problem.
> >
> > When I look at the common libraries between Espresso and Gromacs, I
> > suspect either the gcc or the lamd installations as the source of the
> > problem.
> >
> > However I tested the performance of Espresso with mpi-fake. And the
> > performance is still terrible under Suse 11.1. That leaves gcc as the
> > only candidate.
> >
> > Did anyone else had a similar experience? Any ideas?
> >
> > Greetings from Istanbul,
> >
> > Mehmet

--
Mehmet Sayar - Assist. Prof.  Koc University
Email:address@hidden        Dept. Mechanical Eng.
Phone:+90-212-338-1840        Rumelifeneri Yolu, Sariyer
Fax:  +90-212-338-1548        34450 Istanbul, Turkey