On LIGER, computing hours are allocated per project and with accounting differentiation between CPU and GPU hours.
The accounting hours consumed by your jobs are determined on the basis of:
- The number of reserved physical cores × the elapsed time for a CPU or GPU job.
- Or/and the number of reserved GPUs × the elapsed time for a GPU job.
For a GPU type job, the number of reserved GPUs taken into account for the job accounting is not necessarily equal to the number of GPUs requested via the Slurm directive
#SBATCH --gres=gpu:....Indeed, an adjustment can be made according to the number of CPUs which is also requested for the job. For example, requesting a single GPU from a node (i.e. 1/4 of the GPUs) via
#SBATCH --gres=gpu:1and half of the CPUs of the node, leads to the reservation of half of the resources of the node. The job accounting is then calculated on the basis of a reservation of half of the GPUs (so as if you had requested
#SBATCH --gres=gpu:4depending on the type of node).
Note also that during an execution in exclusive mode (the
--exclusive option of the sbatch command or the Slurm directive
#SBATCH --exclusive), you reserve all resources on Turing node:
- 48 physical cores for cpu partitions.
- 48 physical cores and 4 GPUs for default gpu partition.
The accounting will then be on the basis of:
- The number of reserved nodes × 48 cores × elapsed time for a CPU job.
- The number of reserved nodes × 4 GPUs × elapsed time for a GPU job in default gpu partition..
You can consult your project allocation by using the
Mybalance command or SLURM commands.