DAC, AEC, AOC, and ACC High-Speed Data Transmission Cable Guide

DAC, AEC, AOC, and ACC High-Speed Data Transmission Cable Guide

• 2025-01-10 11:38:28
• By Kaweei.cgj

In today’s fiercely competitive communication industry, enterprises are constantly seeking ways to gain an edge—whether through performance, efficiency, or cost optimization. While many data center upgrades tend to focus on network adapters and switch configurations, one often-overlooked yet highly effective improvement lies in rethinking the interconnect cables themselves.

Currently, four mainstream types of data transmission cables dominate the market: DAC (Direct Attach Cable), AEC (Active Electrical Cable), AOC (Active Optical Cable), and ACC (Active Copper Cable). These solutions differ significantly in terms of transmission medium, performance characteristics, and application scenarios. So, how do they compare—and which one will shape the future of high-speed data communication?

DAC (Direct Attach Cable)

Technical Overview

DAC, also known as direct copper cable, comes in fixed lengths with integrated connectors. The cable and connectors are inseparable, making it a cost-effective, high-speed, and low-loss solution widely adopted in data centers, SANs, and HPC environments. Thanks to its low cost and high efficiency, DAC remains the most popular choice for short-distance interconnections.

Structure

DAC typically consists of silver-plated conductors, foamed insulation, Teflon, PP, and multi-layer shielding. With excellent attenuation performance, low latency, and strong anti-interference capability, DAC supports multiple configurations (2P, 4P, 8P, 16P) and wire gauges (32–24 AWG).

Main Advantages

• High performance: Well-suited for short-distance cabling in data centers.
• Energy efficient: Copper cores provide natural heat dissipation.
• Low power consumption: Passive DAC requires no power, while active DAC consumes only ~440 mW.
• Cost-effective: Significantly cheaper than fiber-based solutions.

AEC (Active Electrical Cable)

Technical Overview

AEC integrates CDR (Clock Data Recovery) and retimer chips at both ends of the cable to amplify, equalize, and reshape signals. This extends copper’s usable distance while maintaining low power consumption and compact design. AEC is particularly critical in enabling DDC (Distributed Disaggregated Chassis) architectures.

Structure

Similar to DAC but enhanced with electronic components, AEC uses silver-plated conductors, Teflon insulation, and advanced shielding. It supports high-frequency broadband transmission with gauges from 28–24 AWG and configurations such as 8P and 16P.

Main Advantages

• Supports 100G–400G speeds with QSFP56, OSFP, and QSFP-DD packages.
• Transmission distance up to 7m.
• Lower power consumption than optical devices (≈25% savings).
• Costs ≈50% less than AOC solutions.
• Smaller diameter and lighter weight compared with DAC, saving up to 70% rack space.
• Enhanced reliability with FEC and retiming functions.

AOC (Active Optical Cable)

Technical Overview

AOC converts electrical signals to optical signals for transmission and vice versa. Equipped with lasers at both ends, AOCs deliver excellent long-distance performance and immunity to electromagnetic interference. However, the use of optical modules and lasers makes them more costly.

Structure

AOCs consist of optical fibers, photoelectric converters, and connectors. Some designs include optical amplifiers or attenuators for optimized signal quality.

Advantages

• Lightweight and compact.
• Immune to EMI, making them reliable in long-distance applications.
• Ideal for inter-switch connections and backbone cabling within data centers.

Disadvantages

• High cost compared to copper solutions.
• Limited laser lifespan (3–5 years).
• Heat generation and energy loss during signal conversion.
• Difficult to repair once failed.

ACC (Active Copper Cable)

Technical Overview

ACC enhances traditional DAC with linear redriver chips that equalize and amplify signals at the receiving end. While lacking full retimer and reshaping functions like AEC, ACC can extend copper’s reach beyond 3m and provide a cost-efficient solution for certain short-link scenarios.

Applications

Supports various transmission rates (10G–800G) across packaging types such as SFP+, QSFP+, QSFP-DD, and OSFP. Though its market is more niche, ACC remains valuable in cost-sensitive deployments with limited distance requirements.

Summary & Market Outlook

When selecting transmission cables, factors such as distance, cost, space, and application scenarios must be carefully evaluated:

• DAC: Best for ultra-short connections, low-cost, high performance.
• AEC: Ideal for dense AI clusters and DDC architectures, balancing cost, power, and space.
• AOC: Superior for long-haul connections, though costly.
• ACC: Niche, cost-driven use cases requiring modest extension beyond DAC.

As data center bandwidth demands rise, DAC faces increasing challenges at higher speeds due to bulkier cable diameters and space inefficiencies. AEC is emerging as a compelling alternative, offering signal recovery, reduced size, and lower cost compared to optical solutions. In fact, industry estimates suggest that the comprehensive cost of 400G AEC is ~53% lower than AOC.

According to LightCounting (Dec 2023), the combined market for AOC, DAC, and AEC reached USD 12B in 2023 and is projected to hit USD 28B by 2028, with respective CAGR growth rates of 15%, 25%, and 45%. This indicates a clear trend: AEC is poised to be a major driver of next-generation high-speed interconnect solutions in data centers.