On 22/02/18 18:49, Miguel Gutiérrez Páez wrote:
What's the real meaning of ntasks? Has cpus-per-task and ntasks the same meaning in sbatch and srun?
--ntasks is for parallel distributed jobs, where you can run lots of independent processes that collaborate using some form of communication between the processes (usually MPI for HPC). So inside your batch script you would use "srun" to start up the tasks. However, unless you code is written to make use of that interface then it's not really going to help you, and so for any multithreaded application you need to use --cpus-per-task instead. Now, you can get fancy and have hybrid applications which can be split up across nodes (individual processes) but each one of those tasks can also use multiple cores at the same time by multi-threading. Of course if your application isn't multithreaded in the first place then you only need to ask for 1 task and 1 core for it anyway! :-) Best of luck, Chris