ARC Cluster GPU Selection Guide

This guide is designed to help you navigate our range of GPU architectures on ARC clusters. Choosing the right hardware depends entirely on the constraints and requirements of your specific workload (e.g., high-accuracy simulation vs. low-power inference).

Part 1: Key Technical Concepts (The Dimensions)

Before making a selection, it helps to understand the technical dimensions that differentiate these GPUs.

Dimension

What it is

Why it Matters

When is it Critical?

Precision (FP64 vs. TF32)

Defines the mathematical accuracy. FP64 (Double Precision) is for rigorous science; TF32 (Tensor Float) and FP16 are for high-speed AI.

Determines if your calculations maintain the required level of accuracy.

HPC Simulations (Need FP64) vs. Deep Learning (Can use TF32/FP16).

Memory Capacity (VRAM)

The GPU’s local memory size (e.g., 80GB, 141GB).

Dictates the maximum size of the model or dataset that can fit onto a single GPU.

Large Language Models (LLMs) or large simulation meshes.

Raw Compute Power (TFLOPS/TF)

The sheer number of operations the GPU can perform per second.

Dictates how fast the core calculation runs.

Training Large Models where speed is the bottleneck.

Power Efficiency (FLOPS/Watt)

The ratio of work done to energy consumed.

Critical for managing cluster operating costs and thermal density.

Inference and Edge Computing where energy consumption matters most.

Interconnect

The speed at which GPUs talk to each other (NVLink, NVSwitch).

Essential when a single job must be split across multiple GPUs (distributed computing).

Any job requiring multiple GPUs (model parallelism, data parallelism).

Terminology Note: Tensor Float (TF) refers to the specialized, optimized data formats (like TF32) used in modern deep learning for faster computation.

Part 2: GPU Comparative Overview (Relative Positioning)

Instead of focusing on raw numbers, this table places the GPUs into performance tiers based on their architectural strengths, making them easier to compare at a glance.

GPU Model

Primary Strength

VRAM (Relative)

Power (TDP)^

Ideal Workload Focus

Tier

B200-180G

Maximum Compute Power

Extremely High

Very High

Training massive foundational models (LLMs).

Apex

H200-141G

Bandwidth & Scale

Very High

High

Large-scale AI training, high-throughput production.

High-End

A100-80G

Balanced Workhorse

High

Medium

Established AI training, complex HPC simulations.

Workhorse

L40S-48G

Versatility & Modernity

High

Medium

Mixed workloads, rendering, medium-scale AI.

Modern/Versatile

A30-24G

Efficiency & Inference

Medium

Low

Production inference, smaller model fine-tuning.

Efficient

V100-16G

Legacy HPC

Medium

Medium

Older codebases, foundational proof-of-concept.

Legacy

T4-16G

Ultra-Efficiency

Small

Very Low

Low-latency inference, small batch size production.

Efficiency Focus

^ TDP: Thermal design power (power consumption).

Part 3: Guidance & Use Case Matrix (Actionable Advice)

Please use this matrix to select the appropriate GPU for your job.

Scenario 1: High-Fidelity Scientific Simulation and Computational Chemistry (HPC)

  • Goal: Accurate physics/chemistry simulations (e.g., Molecular Dynamics, CFD).

  • Constraint: Requires strict mathematical accuracy (FP64).

  • Recommended GPUs (Order by Priority): NVIDIA V100-16G –> NVIDIA A30-24G –> NVIDIA A100-80G.

  • Guidance: The A30 is recommended. The A100 is a modern choice for most HPC tasks. If your code is strictly legacy or smaller in size, try the V100 nodes.

  • ❌ Avoid: T4/L40S (lower FP64 performance) or B200 (overkill/too power-hungry for many simulation jobs).

Scenario 2: Training Large Language Models (LLMs)

  • Goal: Training or fine-tuning models with billions of parameters from scratch.

  • Constraint: Requires maximum memory (VRAM) and high interconnect bandwidth for distributed training.

  • Recommended GPUs (Order by Priority): NVIDIA B200-180G –> NVIDIA H200-141G –> NVIDIA A100-80G.

  • Guidance: Prioritize VRAM first. If you can fit the model on a single A100, that is the most balanced option. For multi-node, memory-intensive jobs, target the H200 or B200.

Scenario 3: General AI Research & Versatility

  • Goal: Mid-sized deep learning experiments, mixed workloads (e.g., vision tasks + data processing), or fine-tuning pre-trained models.

  • Constraint: Needs a strong balance of VRAM and compute without the extreme cost of the top tiers.

  • Recommended GPUs: NVIDIA L40S-48G.

  • Guidance: The L40S offers a fantastic modern balance—it’s highly versatile, efficient, and powerful enough for almost any research job that isn’t an extreme LLM scale-up.

Scenario 4: Deployment & Inference

  • Goal: Running a trained model in real-time or production (e.g., real-time image recognition).

  • Constraint: Requires high performance-per-watt and low latency.

  • Recommended GPUs (Order by Priority): NVIDIA T4-16G –> NVIDIA A30-24G –> NVIDIA L40S-48G.

  • Guidance: If power consumption and operational cost are a major concern, start with the T4. The A30 offers a modern jump in capability for mid-sized production models.

Scenario 5: Commercial Analysis Codes and GPUs

  • Goal: Efficient use of commercial codes.

  • Constraint: Many software like COMSOL and Ansys do not typically use GPUs. Some, like SU2, do.

  • Guidance: Check manuals for the ability of tools to use GPUs.


Technical Appendix (Raw Data)

GPUs available on ARC systems

Here is a list of where you can find them on ARC’s clusters, their configurations, and performance characteristics.

There are 514 GPUs over all clusters.

Architecture

Cluster

Partitions

Number

Memory

Configuration

Interconnect

TDP

FP64

TF64

FP32

TF32

INT8

FLOPS/Watt dp

FLOPS/Watt sp

FLOPS/Watt I8

NVIDIA L40S-48G

Falcon

l40s_normal_q, l40s_preemptable_q

80 (20 nodes, 4 GPU/node)

48G

PCIe, 4 GPUs per node

None

350W

–

–

91.6TF

183TF

733TO

–

523G (TF)

2094G

NVIDIA A30-24G

Falcon

a30_normal_q, a30_preemptable_q

128 (32 nodes, 4 GPU/node)

24G

PCIe, 4 GPUs per node

NVLink Bridge 2-way

165W

5.2TF

10.3TF

10.3TF

82TF

330TO

62.4G (TF)

328G (TF)

1320G

NVIDIA V100-16G

Falcon

v100_normal_q, v100_preemptable_q

72 (36 nodes, 2 GPU/node)

16G

PCIe, 2 GPUs per node

None

250W

7TF

–

14TF

–

250TO

28G (FP)

56G (FP)

1000G

NVIDIA T4-16G

Falcon

t4_normal_q, t4_preemptable_q

18 (18 nodes, 1 GPU/node)

16

PCIe, 1 GPU per node

None

70W

–

–

8.1TF

–

130TO

–

115G (FP)

1857G

NVIDIA A100-80G

TinkerCliffs

a100_normal_q, a100_preemptable_q

112 (14 nodes, 8 GPU/node)

80G

SXM, 8 GPUs per node

NVSwitch HDR IB

400W

9.7TF

19.5TF

19.5TF

156TF

624TO

48.8G (TF)

390G (TF)

1560G

NVIDIA H200-141G

TinkerCliffs

h200_normal_q, h200_preemptable_q

48 (6 nodes, 8 GPU/node)

141G

SXM, 8 GPUs per node

NVSwitch, NDR IB

700W

34TF

67TF

67TF

989TF

3958TO

95.7G (TF)

1413G (TF)

5654G

NVIDIA B200-180G

Owl

b200_normal_q, b200_preemptable_q

32 (4 nodes, 8 GPU/node)

180G

SXM, 8 GPUs per node

NVSwitch

1000W

37TF

37TF

75TF

1100TF

4500TO

37G (TF)

75G (TF)

4500G

NVIDIA A100-80G

CUI

a100_normal_q, a100_preemptable_q

16 (2 nodes, 8 GPU/node)

80G

SXM, 8 GPUs per node

NVSwitch, HDR IB

400W

9.7TF

19.5TF

19.5TF

156TF

624TO

48.8G (TF)

390G (TF)

1560G

NVIDIA A100-80G

Biomed

a100_normal_q, a100_preemptable_q

8 (1 node, 8 GPU/node)

80G

SXM, 8 GPUs per node

NVSwitch, HDR IB

400W

9.7TF

19.5TF

19.5TF

156TF

624TO

48.8G (TF)

390G (TF)

1560G

Technical Legend

  • Memory: Memory available per node.

  • TDP: Thermal design power (power consumption).

  • Precision:

    • FP64: Double precision (high accuracy for scientific computing).

    • TF64: Tensor float 64.

    • FP32: Single precision (standard for many deep learning tasks).

    • TF32: Tensor float 32 (hybrid format for speed in deep learning).

    • INT8: Eight-bit integer representations (used in efficient inference).

  • Performance Units:

    • TF: Teraflops (one trillion operations, 10^{12}).

    • TO: Tera-Operations Per Second (used for INT8).

  • Efficiency (FLOPS/Watt):

    • dp / sp / I8: Double precision / Single precision / Eight-bit integer FLOPS/Watt.

    • Note: “G” means giga (10^9).

    • The numbers in parentheses (FP) or (TF) indicate the type of operation and cannot be directly compared.