I´m running LAMMPS on an SGI Altix system, using 24 CPU´s. The strange
thing is that LAMMPS is using
an enormous amount of virtual memory (134 gig !) and only a very small
amount of real memory (27 meg):
PID USER VIRT RES %CPU TIME+ COMMAND
11261 dacj1984 134g 27m 100 1311:39 lmp_altix
This seems strange for an MD simulation of 1050 particles using an MEAM
Any idea as to what might be going on?
please check the MPI manpage. i remember that at least for some
versions the MPI library was allocating the maximum combined
address space of all nodes for each MPI task (i.e. the total
virtual space will go up, the more nodes you use).
i remember seeing this before with CPMD a long time ago, so
the resolution might be in the CPMD mailing list archive somewhere,
but if i remember correctly, the solution was to set some
specific environment variable and then everything was fine.