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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
80 (20 nodes, 4 GPU/node) |
48G |
PCIe, 4 GPUs per node |
None |
350W |
– |
– |
91.6TF |
183TF |
733TO |
– |
523G (TF) |
2094G |
||
|
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 |
||
|
72 (36 nodes, 2 GPU/node) |
16G |
PCIe, 2 GPUs per node |
None |
250W |
7TF |
– |
14TF |
– |
250TO |
28G (FP) |
56G (FP) |
1000G |
||
|
18 (18 nodes, 1 GPU/node) |
16 |
PCIe, 1 GPU per node |
None |
70W |
– |
– |
8.1TF |
– |
130TO |
– |
115G (FP) |
1857G |
||
|
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 |
||
|
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 |
||
|
32 (4 nodes, 8 GPU/node) |
180G |
SXM, 8 GPUs per node |
NVSwitch |
1000W |
37TF |
37TF |
75TF |
1100TF |
4500TO |
37G (TF) |
75G (TF) |
4500G |
||
|
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 |
||
|
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.