[Pw_forum] << running QE in parallel >>

[I. Camps]

Hello all,

I have a question about running QE in parallel.

I installed LAM/MPI and then compiled QE with the parallel default options.

Then I started running the examples. In the output of example 03, I
get the following:

***************************
 Program PWSCF     v.4.1    starts ...
     Today is 28Aug2009 at 11:30:28

     Parallel version (MPI)

     Number of processors in use:       1

     For Norm-Conserving or Ultrasoft (Vanderbilt) Pseudopotentials or PAW

     Current dimensions of program pwscf are:
     Max number of different atomic species (ntypx) = 10
     Max number of k-points (npk) =  40000
     Max angular momentum in pseudopotentials (lmaxx) =  3
     Waiting for input...
     file O.pz-rrkjus.UPF: wavefunction(s)  2S renormalized
     file C.pz-rrkjus.UPF: wavefunction(s)  2S renormalized

     gamma-point specific algorithms are used


     Subspace diagonalization in iterative solution of the eigenvalue problem:
     Too few procs for parallel algorithm
       we need at least 4 procs per pool
     a serial algorithm will be used

..................
***************************

So as you can see, pw.x is running in serial mode.

How do I solve this issue?

My system:
Processor: AMD Phenom(tm) II X4 940 @ 3GHz (Deneb)
Memory: 8GB RAM
Lam version (from laminfo): 7.1.4
OS: Ubuntu 9.04 64bits (up-to-date)
Environment variables:

export TOPDIR='/software/espresso-4.1'
export BIN_DIR=$TOPDIR/bin
export PSEUDO_DIR=$TOPDIR/pseudo
export TMP_DIR=/scratch
export PARA_PREFIX="mpiexec -n 4"
export PARA_POSTFIX="-npool 1"
PWgui="/software/PWgui-4.1"


Regards,

Camps