[Pw_forum] << running QE in parallel >>

[I. Camps]

Thanks Lorenzo,

> But you are running it with only one processor.
> Having only one processor, you also have less than 4 processors per pool,
> hence matrix diagonalization is done serially.
ok, it is  single processor with 4 cores. In other softwares, each
core is understood as a single processor, so at the end, I am able to
run job paralle in 4 "single" processors. How do QE understand the
number of processors?

> There must be an error in one of these lines, or in the way you combine
> them together. I cannot say which, because I don't use lam and I don't
> have access to the script you've used.
I am using the script that come inside the example tar downloaded from QE site.

> Double-check the script, maybe you only have to replace -n with -np.
Changed, same result.

Thanks in advance.

Camps
___

On Fri, Aug 28, 2009 at 11:57 AM, Lorenzo Paulatto<paulatto at sissa.it> wrote:
> Dear Camps,
> let's have a look at all the output, not just the last line:
>
>
> In data 28 agosto 2009 alle ore 16:42:01, I. Camps <i_camps at yahoo.com.br>
> ha scritto:
>> ...
>>      Parallel version (MPI)
>
> This mean you have actually compiled the parallel version, good!
>
>>      Number of processors in use:       1
>
> But you are running it with only one processor.
>
>>      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
>
> Having only one processor, you also have less than 4 processors per pool,
> hence matrix diagonalization is done serially.
>
> There must be an error in one of these lines, or in the way you combine
> them together. I cannot say which, because I don't use lam and I don't
> have access to the script you've used.
>
>> export PARA_PREFIX="mpiexec -n 4"
>> export PARA_POSTFIX="-npool 1"
>> PWgui="/software/PWgui-4.1"
>
> Double-check the script, maybe you only have to replace -n with -np.
>
> best regards.
>
>
> --
> Lorenzo Paulatto
> SISSA  &  DEMOCRITOS (Trieste)
> phone: +39 040 3787 511
> skype: paulatz
> www:   http://people.sissa.it/~paulatto/
>
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