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Casper Node Types

Targeting a Casper Node Architecture

Tip

This page is written with the assumption that you have some experience using PBS Pro to schedule compute jobs. If you are not yet familiar with job submission, we recommend you review our PBS Pro documentation first.

Casper is a heterogeneous system that has several node architectures. The tables below provides architecture specifications and example PBS select statements to target a specific node type. Targeting a specific node may impact scheduler time, particularly for architectures with low node counts. The PBS select statements are basic examples to request the node and you will likely want to modify the select parameters to better suit your job workflow needs.

Be mindful that these examples only show a way to guarantee the scheduler gives you that node type. There are instances where modifying the example CPU count may overlap with other node types. A specific example would be selecting #PBS -l select=1:ncpus=4 which could place you on any of the High-Throughput Computing node types.

Two parameters that are helpful for targeting node types are cpu_type and gpu_type. The tables below provides examples on how to use them and if you need to use them for requesting a node type.

Info

The examples below do not include optional the ompthreads=X argument for OpenMP threads but can be added if you need hybrid parallelism for your job. The mpiprocs=X setting is omitted except in cases where a GPU is requested since the GPUs underlying communication method requires a MPI rank for each GPU.

Resource Selection

The PBS select statements in this table provide ranges of resources for each node type. Ranges are italicized within brackets of the select statement. However, you cannot provide ranges as part of the select statement using PBS; it must be a static value. For example, the H100 nodes would allow a minimum resource request:

-l select=1:ncpus=1:mpiprocs=1:mem=10gb:ngpus=1:gpu_type=h100
up to the maximum resource request:
-l select=1:ncpus=64:mpiprocs=4:mem=985gb:ngpus=4:gpu_type=h100

Shared vs. Exclusive requests

The maximum resource request will always provide you with an exclusive node. Requesting less than the maximum resources will likely place you on a shared node with other users.

Requesting fewer resources will result in shorter queue times. Requesting an exclusive node will be most performant but will result in longer queue times.

Node Type CPU Cores Core Speed Node Memory GPU GPU Memory Node Count PBS Select Statement
High-Throughput Computing Intel Cascade Lake 34 2.6GHz 354 GB 62 -l select=1:ncpus=[1-34]:mem=[10-354]gb:cpu_type=cascadelake
AMD Epyc 9554P 62 3.1GHz 733 GB 64 -l select=1:ncpus=[1-62]:mem=[10-732]gb:cpu_type=genoa
Large Memory Intel Cascade Lake 36 2.3GHz 1500 GB 2 -l select=1:ncpus=[1-36]:mem=[733-1500]gb:cpu_type=cascadelake
AMD Epyc 9554P 62 3.1GHz 1536 GB 6 -l select=1:ncpus=[1-62]:mem=[733-1525]gb:cpu_type=genoa
Data & Visualization Intel Skylake 36 2.3GHz 384 GB GP100 16 GB 9 -l select=1:ncpus=[1-36]:mem=[10-384]gb:ngpus=1:gpu_type=gp100
Intel Skylake 36 2.3GHz 384 GB A100 40 GB 3 -l select=1:ncpus=[1-36]:mem=[10-384]gb:ngpus=1:gpu_type=a100_40gb
AMD EPYC 9474F 48 3.6GHz 733 GB L40 48 GB 6 -l select=1:ncpus=[1-48]:mem=[10-732]gb:ngpus=1:gpu_type=l40
ML & GPGPU Intel Cascade Lake 36 2.6GHz 768 GB V100 (x4) 32 GB 4 -l select=1:ncpus=[1-36]:mpiprocs=[1-4]:mem=[10-768]gb:ngpus=[1-4]:gpu_type=v100_4way
Intel Cascade Lake 36 2.6GHz 1152 GB V100 (x8) 32 GB 6 -l select=1:ncpus=[1-36]:mpiprocs=[1-8]:mem=[10-1152]gb:ngpus=[1-8]:gpu_type=v100_8way
AMD EPYC Milan 128 2.45GHz 992 GB A100 (x4) 80 GB 8 -l select=1:ncpus=[1-128]:mpiprocs=[1-4]:mem=[10-992]gb:ngpus=[1-4]:gpu_type=a100_80gb
Intel Xeon Gold 6430 64 2.10Ghz 985 GB H100 (x4) 80 GB 2 -l select=1:ncpus=[1-64]:mpiprocs=[1-4]:mem=[10-985]gb:ngpus=[1-4]:gpu_type=h100
AMD MI300A Zen 4* 96 (24 per APU) 3.70Ghz 470 GB MI300A CDNA3 (6 per APU) 128 GB 2 -l select=1:ncpus=[1-96]:mem=[10-470]gb:ngpus=4:gpu_type=mi300a

*MI300A nodes are currently exclusive-use only, and so ngpus must be equal to 4. Other submissions will be rejected.

Accelerator Node Table

The table below provides all possible options for selecting an accelerator architectures on Casper. These values can be used for the gpu_type argument in PBS select statements to allow targeting of a single node architecture or the first available GPU matching the chosen compute capability.

Execution Queue Node Type CC / Arch GPU GPU_mem GPU_num
nvgpu 4x V100 32gb cc70 v100 v100_32gb v100_4way
8x V100 32gb cc70 v100 v100_32gb v100_8way
1x A100 40gb cc70, cc80 a100 a100_40gb a100_1way
4x A100 80gb cc70, cc80 a100 a100_80gb a100_4way
4x H100 80gb cc70, cc80, cc90 h100 h100_80gb h100_4way
amdgpu 4x MI300A gfx942 mi300a mi300a_4way
vis 1x GP100 vis gp100 gp100_16gb
1x L40 vis l40 l40_45gb

High-Throughput Computing

These nodes are for general purpose CPU only workflows. They offer the highest availability for small jobs and will generally have shorter queue times than other node types.

For the High-Throughput Computing nodes, requesting less than 350GB will ensure that you are routed to the htc queue with shorter wait times.

Large Memory Nodes

Select statements that have memory values greater than 733GB are routed to the largemem queue. There are fewer nodes that are assigned the largemem flag so queue times may be longer if you request enough memory to land on this routing method.

Machine Learning and General Purpose GPUs

These GPUs provide hardware and software capabilities for GPU accelerated parallel computational workloads. Their advanced architectures are more performant for Machine Learning, AI, large dataset processing, and simulations compared to the Data and Visualization GPUs.

Data & Visualization

These nodes are primarily used for running applications that either have a Graphical User Interface (GUI) or provide visual output of data. A list of common applications that will benefit from the GPUs of these nodes can be found in the Data Analysis and Visualization section.

The L40 nodes are also capable of basic GPGPU tasks like AI inference and are less utilized than the nodes within the GPGPU queue. This could significantly reduce your wait time in the queue.

Info

Data and Visualization node type requests will be submitted to the vis queue and these GPUs are shared among multiple users on a node. The maximum selectable ngpus is one and exclusive access cannot be guaranteed on the Data and Visualization node types. If you need exclusive node access, use the ML & GPGPU node types.