Link to section 'Questions' of 'Questions' Questions
How do I know Non-uniform Memory Access (NUMA) layout on Brown?
- You can learn about processor layout on Brown nodes using the following command:
brown-a000:~$ lstopo-no-graphics
- For detailed IO connectivity:
brown-a000:~$ lstopo-no-graphics --physical --whole-io
- Please note that NUMA information is useful for advanced MPI/OpenMP/GPU optimizations. For most users, using default NUMA settings in MPI or OpenMP would give you the best performance.
Why cannot I use --mem=0 when submitting jobs?
Link to section 'Question' of 'Why cannot I use --mem=0 when submitting jobs?' Question
Why can't I specify --mem=0 for my job?
Link to section 'Answer' of 'Why cannot I use --mem=0 when submitting jobs?' Answer
We no longer support requesting unlimited memory (--mem=0) as it has an adverse effect on the way scheduler allocates job, and could lead to large amount of nodes being blocked from usage.
Most often we suggest relying on default memory allocation (cluster-specific). But if you have to request custom amounts of memory, you can do it explicitly. For example --mem=20G.
If you want to use the entire node's memory, you can submit the job with the --exclusive option.