[lammps-users] strange problem with output

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1

Hi everyone,

I encountered a strange problem while running lammps on my computer, but I am pretty sure it is not
related to lammps. I wonder if anyone of you came into this before or if you have a solution of this.

Whenever I used all the 4 processors on my computer to run lammps, it will create the log.lammps file
and the dump file as well. The output to these files might be normal in the beginning, but after a while,
it just stopped writing to them. While when I use “top” to check the performance of the computer, all
lmp processes use 100% of the processors.
The same problem also exists if I use 3 processors, but it won’t happen if I use 1 or 2 processors.

My computer has 4 Intel® Xeon® CPU X3220 @ 2.40GHz, and runs with ubuntu 9.10; the compiler
is g++ (Ubuntu 4.4.1-4ubuntu8) 4.4.1 with openmpi 1.3.2.

Thanks.

Lingti

2

you're right - it doesn't sound like a LAMMPS issue. If your
computer only has 4 procs and you are using more than all the memory,
then it is possible you have gone into a swapping mode, which
will make you run very slowly (for any program including LAMMPS)

Steve