800G DAC is a direct high-speed cable used within data centers that supports a data transmission rate of 800 gigabits per second. It is mainly used to connect servers, switches, GPU computing systems and other devices inside the cabinet, and is a key physical layer component for building an 800G network.

Basic Composition and Types  

Consisting of copper cables paired with high-speed connectors (e.g., QSFP‑DD, OSFP) fixed at both ends, they are categorized into Direct Attach Copper cables (DAC), Active Copper Cables (ACC), and Active Electrical Cables (AEC).  

Key Technical Parameters  

- Speed: 800 Gbps (8 lanes *100 Gbps PAM4 modulation).  

- Main Reach: DAC typically 1–3 m; AEC can reach 3–5 m or longer.  

- Power Consumption: Extremely low (near 0 W for passive DAC, about 1–2 W/port for active cables), far lower than optical modules.  

- Latency: Sub‑nanosecond, extremely low.  

Core Application Scenarios  

- Short‑reach intra-rack connections in data centers: e.g., Top‑of‑Rack (ToR) switch to server, or switch‑to‑switch cluster interconnects.  

- AI/High‑Performance Computing clusters: Leading vendors prioritize DAC whenever possible to maximize energy efficiency and minimize latency.  

Core Advantages  

- Ultra‑low Cost: Port cost can be >40 % lower than equivalent 800 G optical modules.  

- Ultra‑low Power and Latency: Significantly reduces data‑center operational expenses and cooling overhead.  

- Plug‑and‑play, High Reliability: Passive design requires no configuration and exhibits low failure rates.  

800 G DAC serves as a foundational technology for short‑reach, low‑cost, high‑efficiency connections inside data centers, with its importance becoming increasingly prominent in the era of AI computing.