GPU Nodes

New HPC Documentation Website!

New documentation is coming that will replace our current Confluence website (the one you're viewing right now). We will be sending an announcement on when the site will go live. Interested in taking a peek? Check out this page for the beta version. Note: the URL is likely to change.

New GPUs on Ocelote!

We have recently added 22 new P100 GPUs to Ocelote. Need to request multiple GPUs on a node and you're finding Puma queue times too slow? You can now request two GPUs per node on Ocelote using --gres=gpu:2.


Compute Resources

More detailed information on system resources can be found on our Compute Resources page.

Containers with GPU Support

Singularity containers are available as modules on HPC for GPU-supported workflows. For more information, see our documentation on Containers.

Accessing GPUs

Information on how to request GPUs using SLURM can be found in our SLURM Documentation.


For a list of training resources related to GPU workflows, see our Training documentation.


Cluster Information



Puma has a different arrangement for GPU nodes than Ocelote and ElGato. Whereas the older clusters have one GPU per node, Puma has four. This has a financial advantage for providing GPU's with lower overall cost, and a technical advantage of allowing jobs that can use multiple GPU's to run faster than spanning multiple nodes.  This capability comes from using a newer operating system.  
Each node has four Nvidia V100S model GPUs. They are provisioned with 32GB memory compared to 16GB on the P100's.



Ocelote has 46 compute nodes with Nvidia P100 GPUs that are available to researchers on campus. The limitation is a maximum of 10 concurrent jobs. Previously, one node with a V100 was available, but it has since been replaced with a P100. Tasks which require multiple GPUs must either request multiple nodes on Ocelote, or use Puma's GPU nodes.

Cuda Modules

Nvidia Nsight Compute (the interactive kernel profiler) is not available. In response to a security alert (CVE-2018-6260) this capability is only available with root authority which users do not have. 

The latest Cuda module available on the system is 11.8, with several older versions also available.The Cuda driver version can be queried with the nvidia-smi command. To see the modules available, in an interactive session simply run:

$ module avail cuda

-------------------- /opt/ohpc/pub/moduledeps/gnu8-openmpi3 ---------------------

--------------------------- /opt/ohpc/pub/modulefiles ---------------------------
   cuda11-dnn/8.0.2        cuda11-sdk/20.7         cuda11/11.0
   cuda11-dnn/8.1.1        cuda11-sdk/21.3         cuda11/11.2
   cuda11-dnn/8.9.2 (D)    cuda11-sdk/22.11 (D)    cuda11/11.8 (D) 


The OpenACC API is a collection of compiler directives and runtime routines that allow you to specify loops and regions of code in standard C, C++, and Fortran that you can offload from a host CPU to the GPU.

We provide two methods of support for OpenACC

  1. We support OpenACC in the PGI Compiler.  The PGI implementation of OpenACC is considered the best implementation.  
    "module load pgi" on Ocelote. If you are on a GPU node from an interactive session you can run "pgaccelinfo" to test functionality.  Remember that the login nodes do not have GPUs or software installed.  
    A useful getting-started guide written by Nvidia is available here: 

  2. We support OpenACC in the GCC Compiler 6.1 which is automatically loaded as a module when you log into Ocelote.  Verify with "module list".
    The GCC 6 release includes a much improved implementation of the OpenACC 2.0a specification.
    A useful quick reference guide is available from:


Many applications have been optimized to run faster on GPU's. These include:

NAMDInstalled as a module$ module load namd
VASPA restricted license version is installed; only available to licensed users$ module load vasp
GROMACSInstalled as a module$ module load gromacs
LAMMPSInstalled as a module$ module load lammps
ABAQUSInstalled as a module and available as an application through Open OnDemand$ module load abaqus
GAUSSIANInstalled as a module. See these notes.$ module load gaussian/g16
MATLABInstalled as a module and available as an application through Open OnDemand. Review the GPU Coder on their website$ module load matlab
ANSYS FluentInstalled as a module and available as an application through Open OnDemand$ module load ansys
RELIONAvailable as a Singularity container or as a module.$ module load relion
ML and DL FrameworksSee the section below.

Python ML/DL including Nvidia RAPIDS 

The minimum version of Python that is supported is 3.6:

numbaRAPIDS: numba is for Cuda programming
cumlRAPIDS: Cuda Machine Learning has many ML algorithms like K-means, PCA and SVM
cudfRAPIDS: Cuda Dataframes supports loading and manipulating datasets
tensorflowTensorFlow is an open source software library for numerical computation using data flow graphs.
torchPyTorch supports tensor computation and deep neural networks
caffe2A deep learning framework
tensorrtInference server for deep learning
tensorboardVisualization tool for machine learning