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hanna-ford edited this page Sep 22, 2022 · 18 revisions

The University of Arkansas, Fayetteville (UAF) and the University of Arkansas for Medical Sciences (UAMS) have signed a Memorandum of Understanding (MOU) forming the Arkansas Research Computing Collaborative (ARCC), also known as the Arkansas Research Platform (ARP), in order to share, enhance, and manage existing and future high performance and cloud computing resources and associated mass storage capabilities.

1. Comparison of Clusters

The following table approximates a comparison of the two primary HPC resources available through the ARP

Cluster Name Grace (UAMS) Pinnacle (UAF)
# of Compute Nodes 96 Xeon 100 dual Xeon
96 Xeon Phi 50 dual AMD
4 Xeon 248 varies
# of Cores per Node 28 32
64 64
24 varies
Memory per Node 128 Gb 192 Gb
80 cores x 384; 16 cores x 192 1024
128 varies
# of Nodes with GPUs 4 x 2 Nvidia GPUs 22 x 1 Nvidia GPU; 50 x 70 Nvidia GPUs

2. Grace at UAMS

The primary system at UAMS is named Grace, after Rear Admiral Grace Hopper, a pioneer in computer science. Grace is supported by 7 management/login/storage interface nodes. All components are interconnected via 100Gbps Omnipath interconnects and are attached to internal storage and the Internet (both commercial and I2) with redundant 10Gbps Ethernet interfaces. Intermediate storage is provided by a 1PB NAS and long term/backup storage is provided by a 4.2 PB object storage system (Dell/EMC ECS appliance).

3. Pinnacle at UAF

The primary system at UAF is named Pinnacle, after "Pinnacle Mountain" in central Arkansas. Pinnacle is supposted by ~35 management/login/storage interface nodes, including 14 VM ssh login nodes. All components are interconnected via 100Gbps Infiniband interconnects for multi-node computing and are attached to external storage and the Internet.

4. Open OnDemand vs Command Line Interface

Both Grace and Pinnacle support both the Open OnDemand web interface and Command Line Interface, but what are the differences?

Open OnDemand, or OOD, is an intuitive, innovative, and interactive interface to remote computing resources. Read more about OOD:

Command Line Interface, or CLI, refers to a command line program that accepts text input to execute operating system functions (source:

Task Open OnDemand Command Line Interface
Use Interactive Apps, such as RStudio, Jupyter, and MATLAB Yes No
Use an Interactive Desktop Yes No
Run a job interactively through application software, such as R, python, and matlab Yes Yes
Use a single core on a single node No Yes
Use all the cores on a single node Yes Yes
Use multiple cores on multiple nodes No Yes
Move files within /storage/home Yes Yes

5. How to contact ARP administrators

Each resource within the ARP has a technical staff that administers the cluster.

5.1. Grace (UAMS)

At the University of Arkansas for Medical Sciences the Grace cluster is administered by Dr. Lawrence Tarbox.

To report a problem, or to request assistance, please send an email to

5.2. Pinnacle (UAF)

At the University of Arkansas, Fayetteville the Pinnacle cluster is administered by Dr. David Chaffin and Dr. Pawel Wolinski. Jeff Pummill provides user support and assistance.

To report a problem, or to request assistance, please send an email to

5.3. Minimal, Reproducible Examples

When requesting assistance or reporting problems, please try to provide as much detail as possible.

Consider reading up on Minimal, Reproducible Examples (sometimes called “reprex”, “min-reprex”, “repro” or just “example”)