Selection Guide for 800G Active Optical Cables for Data Center Interconnection

800G AOCs are ideal for medium- to long-reach data center interconnects, offering high bandwidth, low latency, and low power consumption, making them suitable for AI, HPC, and cloud fabrics.

Key Considerations for Selecting 800G AOCs

1. Distance and Reach AOCs are designed to bridge the gap between short-reach DACs and longer-reach optical transceivers. Typical 800G AOCs support distances up to 100 meters, making them suitable for intra-row, inter-rack, and spine-leaf connections in high-density data centers . For shorter distances (under 5 meters), DAC or AEC may be more cost-effective, while AOCs excel in medium-range deployments where copper solutions are impractical . 2. Power Consumption AOCs consume under 5 W per cable, even in high-density racks, which helps minimize thermal load and cooling costs . This is significantly lower than traditional optical transceivers, making AOCs a power-efficient choice for large-scale AI or HPC clusters . 3. Latency and Performance AOCs provide ultra-low latency comparable to DACs, while supporting 800 Gb/s aggregate bandwidth over four 200 Gb/s parallel lanes. This ensures line-rate performance for GPU-to-GPU aggregation, AI/ML clusters, and HPC workloads . PAM4 DSP technology and VCSEL optics optimize signal integrity and reduce complexity . 4. Form Factor Compatibility 800G AOCs are available in QSFP-DD, OSFP, and QSFP112 form factors. Selection depends on switch port density, thermal constraints, and rack layout. OSFP modules are often preferred for higher thermal headroom, while QSFP-DD is widely supported in existing infrastructures . 5. Diagnostics and Reliability Modern AOCs include I²C digital diagnostics, providing real-time monitoring of optical power, temperature, voltage, and signal-to-noise ratio. This allows proactive detection of issues before they impact network performance . 6. Deployment Scenarios

• Intra-rack connections: DAC or short AOCs for minimal latency and cost.
• Inter-rack or row-to-row: AOCs provide optimal reach without excessive power overhead.
• Spine-leaf fabrics: AOCs support oversubscribed designs with minimal latency and high bandwidth . 7. Upgrade Path Considerations When planning for future 1.6T networks, AOCs offer a flexible migration path. Proper selection today ensures that the fiber plant and switch infrastructure can accommodate higher-speed upgrades without complete rewiring .

Summary Recommendation

• Use DAC for distances under 5 meters to minimize cost and power.
• Use AEC for intermediate distances (up to 9 meters) with lower power than optical.
• Use AOC for medium- to long-reach connections (up to 100 meters) where low latency, high bandwidth, and low power are critical.
• Consider form factor, thermal budget, and diagnostics when selecting AOCs for high-density AI or HPC deployments.
• Plan the interconnect mix based on measured topology distances to avoid unnecessary cost or deployment failures . By following these guidelines, data center engineers can ensure scalable, efficient, and reliable 800G interconnects that support current AI/HPC workloads and future 1.6T upgrades.