How Do I Use and Check GPUs on HPC Clusters?
GPUs available on the HPC clusters can be listed by using the valar-nodes and kuacc-nodes commands.
Example Output

Requesting GPUs in a SLURM Job
You can request GPUs in your SLURM job script using the --gres (Generic RESources) flag.;
#SBATCH --gres=gpu:tesla_t4:1
This requests 1 Tesla T4 GPU. You can also request any GPU type using:
#SBATCH --gres=gpu:1
or combine with a constraint to reserve a specific type:
#SBATCH --gres=gpu:1
#SBATCH --constraint=tesla_t4
GPU Specifications on VALAR
Here is the updated list of GPUs available on VALAR nodes:
GPU Type | Memory | CUDA Cores | Node Names |
Tesla T4 | 16GB | 2560 | ai[01–10], ag04 |
Tesla V100 | 32GB | 5120 | ai[11–14], it[01–04] |
Ampere A40 | 48GB | 10752 | ai[18–26] |
RTX A6000 | 48GB | 10752 | ai[15–17] |
Lovelace L40S | 48GB | 10752 | ai[27–35], star[01–04] |
GTX 1080 Ti | 11GB | 3584 | ag01 |
Tesla A100 | 80GB | 6912 | rk02 |
Notes:
Tesla T4: Optimized for inference workloads.
Tesla V100: Equipped with Tensor Cores, suitable for deep learning.
Ampere A40: Supports AI, rendering, and multi-workload acceleration.
RTX A6000: High-end visual computing and AI tasks.
Lovelace L40S: Data center GPU for AI and graphics-intensive tasks.
GTX 1080 Ti: Legacy high-performance GPU for smaller workloads.
Tesla A100: Top-tier AI and HPC GPU with massive memory.
Monitoring GPUs While Running Jobs
You can monitor GPU usage on compute nodes via nvidia-smi. SSH to the node running your job:

Memory Usage shows the GPU memory currently used by your jobs.
Processes lists which jobs are using which GPU. You can check the process owner using ps aux | grep <PID>.
This helps avoid over-reserving high-end GPUs (like Tesla V100) for jobs that only need a small amount of GPU memory.
Best Practices
Reserve only the number and type of GPUs your job actually needs.
Use nvidia-smi to monitor GPU utilization during test runs.
Cancel idle or finished GPU jobs to free resources for other users.
Combine --gres with constraints if you need a specific GPU type.