Hands-on: Hyper-parameter tuning the PyTorch model using Ray

Exercises on the course GitHub.

Q&A

1. In run.sh in the reference solution, memory is specified to be 0 (#SBATCH --mem=0). Why does this work? Why do we not need to specify e.g. 480G?

   • (Gregor) --mem=0 will use all the available memory on the node, it's just a faster way of specifying "use all the available memory on the node". --mem=480G works as well.

   • (Kurt) but it is actually better to specify that you want 480G as there is a subtle difference: Asking for 480G guarantees that you will get 480G. You can get a lot less with --mem=0 if, e.g., due to a memory leak in the system software - which has happened - more memory is consumed by the OS. So asking --mem=480G guarantees you a node that is healthy at least in that respect.