The ARGO cluster now enforces hard memory limits on jobs.  The default memory limit for a job is 2 GB per core per node.  So if you request 4 cores on a single node your job will be limited to 8 GB.  If your job exceeds the amount of memory allocated it will be killed and the state recorded as OUT_OF_MEMORY.  It is best to request some small increment more that your job actually requires as it is hard to precisely estimate the memory requirements in advance.  You can request a set amount of memory by specifying

#SBATCH --mem=XX[K|M|G|T]
e.g. to request 8 GigaBytes use:
#SBATCH --mem=8G

Where XX represents the amount of memory your job requires plus some small (10%) padding and the suffix K|M|G|T denotes, Kilo-, Mega-, Giga- and Tera- Bytes respectively.

Alternatively, it may be preferable to specify a memory per core limit :

#SBATCH --mem-per-cpu=XX[K|M|G|T]

The sacct command can display the memory used by prior jobs if you wish to review the actual memory consumption and fine-tune your memory request for future runs.  For example:

> sacct -o JobID,JobBane,Start,MaxRSS,state -S mm/dd

here a start is specified in month/day form.