What is 400G QSFP-DD AOC?

What is 400G QSFP-DD AOC?

OptechTW

400G QSFP-DD AOC – High-Speed Optical Interconnects for the Future

In the era of exponential data growth, the need for ultra-high-speed and low-latency connectivity within and between data centers is more critical than ever. 400G QSFP-DD AOC (Active Optical Cable) is a next-generation optical interconnect solution designed to deliver superior performance in hyperscale cloud, AI, and enterprise environments.

What is 400G QSFP-DD AOC?

The 400G QSFP-DD AOC is a pre-terminated cable assembly with optical transceivers on both ends, based on the QSFP-DD (Quad Small Form Factor Pluggable Double Density) form factor. It supports 400 Gbps transmission rates over OM3/OM4 multimode fiber, making it ideal for short-reach applications up to 100 meters.

Key Specifications:

  • Interface: QSFP-DD to QSFP-DD

  • Data Rate: 400Gbps (8x 50G PAM4)

  • Cable Length: Typically 1m to 100m

  • Fiber Type: Multimode (OM3/OM4)

  • Power Consumption: <10W (typical)

Application Scenarios of 400G AOC

1. Spine-Leaf Architecture in Data Centers
400G AOC cables are widely used to connect spine and leaf switches, supporting ultra-fast East-West traffic with minimal latency.

2. GPU Clusters and AI Supercomputing
In high-performance computing (HPC) and AI training setups (e.g., with NVIDIA H100 GPUs), 400G AOCs provide low-latency and high-bandwidth interconnects between compute nodes.

3. Short-Distance Inter-Rack Connections
For connections within the same row or across adjacent racks, 400G AOC reduces deployment complexity, cost, and EMI compared to direct attach copper cables.

Advantages of Using 400G QSFP-DD AOC

  • High Bandwidth & Low Latency: Supports 400Gbps with minimal latency, ideal for real-time data processing.

  • Plug-and-Play Deployment: No need for transceiver modules or patch cords — lowers installation time and maintenance complexity.

  • Lightweight & Flexible: Easier cable management compared to passive copper solutions.

  • Cost-Effective for Short Reach: Provides an affordable high-speed solution within 100m range, especially for hyperscale deployments.

  • Energy Efficient: Consumes less power than individual optical transceivers paired with patch cords.

Conclusion

As networks evolve to meet the demands of AI, machine learning, and high-throughput cloud applications, 400G QSFP-DD AOC stands out as a crucial solution for short-reach, high-performance interconnects in data centers.

For data center architects looking to optimize cost, speed, and scalability, deploying 400G AOC is a forward-thinking strategy.

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