ABINIT Discussion Forums

I'm not sure if this is the right forum to put this in, but it seems like a good first shot. I've been running abinit 6.0.3 on an x86_64_gnu_4.4 quad-core 8gb machine, compiled with mpirun, and everything works well for small systems. For systems that require larger than 2gb of memory with 4 processors, my jobs get killed due to an out of memory issue. When I top on a job that should take 2.5GB of memory, I see that there are 4 abinit processes, each of which has allocated 2.5 GB of virtual memory, and my job crashes during the first iteration. Do I need to have enough memory so that each processor has access to 2.5gb of memory, or is something misconfigured?

Hello,

in practice, yes:

1) abinit uses a bit more memory than announced (only the biggest arrays are counted) - in some exotic cases the estimation is completely off (not for normal ground state or DFPT though)

2) almost always, the memory must be _real_ - no counting on linux swap spaces etc... which are usually for programs which are not actively running. If you want to reduce your footprint, check mkmem, or distribute over more processors (not on your machine, though).

matthieu

Thanks for the quick response. So then as I understand it, having 8gb on my machine, if I want to use all 4 processors, I'm limited to jobs which require less than 2gb for the largest array, correct?

bump

Yes in case your "jobs" meant processes : you send one job that splits into 4 processes ; each of those uses less than 2 GB of RAM.