The ABINIT Users Mailing List ( CLOSED )

[Maurice de Koning <dekoning@ifi.unicamp.br>]

Dear all,

I noticed strange behavior while using the bands/fft parallelization 
features of abinip (compiled with -DMPI_FFT preprocessor flag),
running on an SGI Altix system with 16 CPU´s.

The calculation in question involves a geometry optimization using only 
the gamma point:

1) The first calculation was run using the parameters:

npbands=8, npfft=2

This calculation runs fine and the geometry optimization converges 
without any trouble.

2) Then I tried a different distribution, using the parameters

npbands=16, npfft=1

According to the documentation, this should be more efficient than the 
first choice.

But while running this calculation something strange happens. After a 
while, only a few
of the 16 CPU´s are actually processing, with the remainder in 
"uninterruptable sleep".
This already occurs during the first SCF cycle, effectively interrupting 
the progress of
the calculation.

Any ideas?

Cheers,

Maurice