[Pw_forum] Effect of kernel parameters to calculation of larger systems

[Axel Kohlmeyer]

On Tue, 29 May 2007, obm wrote:

> Hi to all,

hi to <unknown>!

> 	Does configurable kernel variables like shmmax have any impact on the
> size of the system that can be calculated?

not directly, however some compilers, e.g. the intel fortran
compilers require a larger stack segment, than what is the
default, and some MPI libraries or interconnects, e.g. infiniband
with OpenMPI needs the maximum locked memory area to be much
enlarged, can required changes in the default settings, either
in the kernel or in ulimit/pam settings. however, those are
not specific to the quantum espresso software (unlike, e.g., 
gaussian, that needs a large shared memory segment for its
_internal_ shared memory parallelization).

cheers,
   axel.

> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
> 

-- 
=======================================================================
Axel Kohlmeyer   akohlmey at cmm.chem.upenn.edu   http://www.cmm.upenn.edu
   Center for Molecular Modeling   --   University of Pennsylvania
Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323
tel: 1-215-898-1582,  fax: 1-215-573-6233,  office-tel: 1-215-898-5425
=======================================================================
If you make something idiot-proof, the universe creates a better idiot.