QDD-8X100G-FR vs. QDD-2X400G-FR4: High-Speed Optical Solutions for Next-Generation Networking

As data centers, AI computing, and high-performance networking evolve, the demand for scalable, high-bandwidth optical transceivers has surged. The QDD-8X100G-FR and QDD-2X400G-FR4 modules are two key solutions designed to address different network expansion needs, supporting high-speed aggregation, AI cluster connectivity, and hyperscale data center deployments.

This article explores the technical specifications, applications, and benefits of these high-density QSFP-DD transceivers, helping organizations choose the right module for scalable 100G and 400G networking.

1. Overview of QDD-8X100G-FR & QDD-2X400G-FR4

Transceiver Model Total Bandwidth Lane Configuration Distance Fiber Type Form Factor
QDD-8X100G-FR 800G 8x100G FR (4WDM-2) 2km Single-mode fiber (SMF) QSFP-DD
QDD-2X400G-FR4 800G 2x400G FR4 (4x100G per channel) 2km Single-mode fiber (SMF) QSFP-DD

Both modules utilize the QSFP-DD (Quad Small Form-Factor Pluggable – Double Density) form factor, supporting 800G total bandwidth but catering to different network deployment scenarios.

2. QDD-8X100G-FR: 8x100G for High-Density Aggregation

🔹 Key Features

  • 800G aggregate bandwidth (8 lanes of 100G)
  • Supports 2km transmission over SMF
  • 4WDM-2 modulation for efficient 100G transmission
  • Ideal for spine-leaf connectivity & AI interconnects

🔹 Use Cases

✔ 100G AI Server Interconnects – Directly connects 100G AI servers, GPUs, and accelerators to a 400G or 800G fabric.
✔ Spine-Leaf Aggregation – Provides multi-lane 100G breakout options for high-density 100G access networks.
✔ Hyperscale Data Centers – Supports multi-tenant, cloud AI computing environments.

🔹 Deployment Example: AI Data Center

  • AI Servers (100G NICs) → QDD-8X100G-FR → 400G/800G AI Leaf Switch
  • Ensures low-latency, high-throughput interconnects for machine learning workloads

🔹 Best for AI-driven, high-density 100G connectivity in modern network fabrics.

3. QDD-2X400G-FR4: High-Speed 2x400G Networking

🔹 Key Features

  • 800G aggregate bandwidth (2 lanes of 400G)
  • Supports 2km transmission over SMF
  • 400G FR4 (4x100G per 400G lane)
  • Designed for high-speed core network links

🔹 Use Cases

✔ 400G Data Center Interconnects (DCI) – Connects spine switches at 400G per channel.
✔ AI Cluster Backbone – Provides ultra-high-speed AI GPU-to-GPU communication.
✔ Cloud & Edge Computing – Reduces congestion in distributed AI inferencing environments.

🔹 Deployment Example: 800G AI Fabric

  • AI Compute Cluster (400G GPUs) → QDD-2X400G-FR4 → 800G Spine Switch
  • Ensures fast, lossless AI training and model processing

🔹 Best for high-speed 400G networking, AI training fabrics, and large-scale data center expansion.

4. QDD-8X100G-FR vs. QDD-2X400G-FR4: Key Differences

Feature QDD-8X100G-FR QDD-2X400G-FR4
Total Bandwidth 800G 800G
Lane Configuration 8x100G 2x400G (4x100G per lane)
Distance 2km 2km
Best for AI Compute & Spine-Leaf Aggregation High-Speed AI Fabric & 400G Data Center Links
Ideal Deployment Multi-100G AI server interconnects Ultra-fast 400G networking

🔹 QDD-8X100G-FR is ideal for connecting multiple 100G devices, while QDD-2X400G-FR4 is optimized for high-speed 400G backbones.

5. Choosing the Right Module for AI & Data Center Networks

✔ Choose QDD-8X100G-FR If:

  • You need high-density 100G connectivity (e.g., AI servers, GPUs, 100G NICs)
  • Your network architecture requires 8x100G breakout links
  • You are deploying spine-leaf switching in hyperscale environments

✔ Choose QDD-2X400G-FR4 If:

  • You require high-speed 400G interconnects for AI or cloud computing
  • Your infrastructure uses 800G core networking
  • You need ultra-low latency for AI model training

6. Conclusion: Scalable 800G Solutions for Next-Gen Networking

Both QDD-8X100G-FR and QDD-2X400G-FR4 provide 800G networking capabilities, tailored for different use cases:

✅ QDD-8X100G-FR is best for multi-lane 100G deployments in AI computing & data centers.
✅ QDD-2X400G-FR4 is optimized for ultra-fast 400G interconnects in AI, cloud, and hyperscale environments.

🚀 Upgrade your AI and high-speed data center networks with cutting-edge 800G solutions!