Navigating Optimal GPU-Module Ratios: Decoding the Future of Network Architecture

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The market’s diverse methods for calculating the optical module-to-GPU ratio lead to discrepancies due to varying network structures. The precise number of optical modules required hinges on critical factors such as network card models, switch models, and the scalable unit count.

Network Card Model

The primary models are ConnectX-6 (200Gb/s, for A100) and ConnectX-7 (400Gb/s, for H100), with the upcoming ConnectX-8 800Gb/s slated for release in 2024.

Switch Model

MQM 9700 switches (64 channels of 400Gb/s) and MQM8700 switches (40 channels of 200Gb/s) are the main types, affecting optical module needs based on transmission rates.

Number of Units (Scalable Unit)

Smaller quantities use a two-tier structure, while larger quantities employ a three-tier structure, as seen in H100 and A100 SuperPODs.

  • H100 SuperPOD: Each unit consists of 32 nodes (DGX H100servers) and supports a maximum of 4 units to form a cluster, using a two-layer switching architecture.
  • A100 SuperPOD: Each unit consists of 20 nodes (DGX A100 servers) and supports a maximum of 7 units to form a cluster. If the number of units exceeds 5, a three-layer switching architecture is required.

Optical Module Demand Under Four Network Configurations

Projected shipments of H100 and A100 GPUs in 2023 and 2024 indicate substantial optical module demands, with a significant market expansion forecasted. The following are four application scenarios:

  • A100+ConnectX6+MQM8700 Three-layer Network: Ratio 1:6, all using 200G optical modules.
  • A100+ConnectX6+MQM9700 Two-layer Network: 1:0.75 of 800G optical modules + 1:1 of 200G optical modules.
  • H100+ConnectX7+MQM9700 Two-layer Network: 1:1.5 of 800G optical modules + 1:1 of 400G optical modules.
  • H100+ConnectX8 (yet to be released)+MQM9700 Three-layer Network: Ratio 1:6, all using 800G optical modules.

For detailed calculations regarding each scenario, you can click on this article to learn more.

Conclusion

As technology progresses, the networking industry anticipates the rise of high-speed solutions like 400G multimode optical modules. FS offers optical modules from 1G to 800G, catering to evolving network demands.

Register for an FS account, select products that suit your needs, and FS will tailor an exclusive solution for you to achieve network upgrades.