DAC vs AOC vs AEC丨Complete Comparison Guide for AI Data Center Interconnect

1. Choosing the Right AI Data Center Interconnect Solution

With the rapid growth of Artificial Intelligence (AI), Large Language Models (LLMs), and high-performance computing (HPC), modern data centers are experiencing unprecedented bandwidth requirements.

AI clusters consisting of thousands of GPUs require extremely high-speed communication between:

• GPU servers

• Network switches

• Storage systems

• Computing nodes

Traditional electrical connections are becoming increasingly challenging due to signal loss, power consumption, and bandwidth limitations.

To address these challenges, high-speed interconnect technologies such as DAC (Direct Attach Copper), AEC (Active Electrical Cable), and AOC (Active Optical Cable) have become essential solutions for AI data center networks.

Each technology has different advantages in terms of:

• Transmission distance

• Power consumption

• Signal integrity

• Cost

• Deployment scenarios

Understanding the differences between DAC, AEC, and AOC helps network engineers select the optimal connectivity solution for AI infrastructure.

C-LIGHT provides advanced high-speed interconnect solutions, including:

• 400G DAC

• 800G DAC

• 800G AEC

• High-speed AOC solutions

supporting next-generation AI data center architectures.

2. What Are DAC, AEC, and AOC?

2.1 DAC (Direct Attach Copper)

DAC, or Direct Attach Copper Cable, is a passive copper-based interconnect solution that transmits electrical signals directly through copper conductors.

Because DAC does not contain active electronic components, it provides:

• Zero additional power consumption

• Lowest latency

• Cost-effective deployment

DAC is mainly used for short-distance connections inside data centers.

Typical applications:

• Server-to-switch connections

• Top-of-Rack (ToR) networking

• In-rack GPU connections

Advantages:

• Low cost

• Simple architecture

• Excellent latency performance

Limitations:

• Limited transmission distance

• Cable thickness increases at higher speeds

C-LIGHT provides high-speed DAC solutions supporting:

• 400G QSFP-DD DAC

• 400G QSFP112 DAC

• 800G OSFP DAC

• 1.6T OSFP DAC

for AI cluster and high-performance computing applications.

2.2 AEC (Active Electrical Cable)

AEC, or Active Electrical Cable, is an advanced copper interconnect solution integrating active signal processing components inside the cable ends.

Compared with passive DAC, AEC improves signal quality through:

• Retimer technology

• Signal regeneration

• Clock and Data Recovery (CDR)

AEC provides longer reach and better signal integrity while maintaining copper-based cost advantages.

Main applications:

• AI GPU cluster connections

• Rack-to-rack interconnection

• High-density switch environments

Advantages:

• Longer reach than DAC

• Improved signal integrity

• Better cable management

• Suitable for high-speed 800G networks

C-LIGHT provides:

• 400G AEC solutions

• 800G OSFP AEC

designed for future AI data center deployments.

2.3 AOC (Active Optical Cable)

AOC, or Active Optical Cable, integrates optical transceivers and fiber cable into a complete interconnect assembly.

Unlike DAC and AEC, AOC transmits data through optical fiber.

Advantages:

• Longer transmission distance

• Lightweight cable structure

• Excellent electromagnetic interference resistance

• Better airflow management

Typical applications:

• Switch-to-switch connections

• AI cluster inter-rack links

• Data center backbone networks

Limitations:

• Higher cost than DAC

• Requires optical conversion components

C-LIGHT provides high-speed AOC solutions for:

• 400G networking

• 800G AI data centers

• High-performance computing systems

3. DAC vs AEC vs AOC: Technical Comparison

4. Application Scenarios in AI Data Centers

4.1 DAC Applications

DAC is ideal for short-distance AI rack connections.

Typical scenarios:

• GPU server to Top-of-Rack switch

• Same rack connections

• Short high-bandwidth links

For example:

AI training clusters often use DAC connections where:

• Distance is less than several meters

• Lowest latency is required

• Cost efficiency is important

4.2 AEC Applications

AEC fills the gap between DAC and optical solutions.

It is suitable for:

• Multi-rack AI systems

• GPU cluster expansion

• High-density networking environments

AEC provides:

• Better signal quality

• Longer copper transmission capability

• Improved installation flexibility

4.3 AOC Applications

AOC is preferred when longer distance and flexible routing are required.

Typical applications:

• AI pod interconnection

• Data center rows

• High-density switch networks

Benefits:

• Thin cable design

• Better airflow

• Longer transmission capability

5. DAC, AEC, and AOC in 400G / 800G / 1.6T Networks

5.1 400G Interconnect

400G has become widely deployed in modern data centers.

Common solutions:

• 400G QSFP-DD DAC

• 400G QSFP112 DAC

• 400G AEC

• 400G AOC

Applications:

• Cloud computing

• AI infrastructure

• Enterprise data centers

5.2 800G Interconnect

800G is becoming the mainstream solution for next-generation AI networks.

AI workloads require:

• Higher bandwidth density

• Lower power consumption

• Faster GPU communication

C-LIGHT 800G solutions include:

• 800G OSFP DAC

• 800G OSFP AEC

• 800G AOC

Supporting:

• AI clusters

• HPC systems

• Large-scale data centers

6. How to Choose Between DAC, AEC, and AOC?

The selection depends on:

Distance

• Short distance → DAC

• Medium distance → AEC

• Longer distance → AOC

Power Budget

• Lowest power → DAC

• Balanced performance → AEC

• Flexible long-distance → AOC

Network Architecture

• Rack-level connection → DAC

• AI cluster interconnection → AEC

• Data center fabric → AOC

7. Why Choose C-LIGHT High-Speed Interconnect Solutions?

C-LIGHT focuses on advanced optical and electrical interconnect solutions for AI data centers and high-performance computing.

Product portfolio includes:

DAC Solutions

• 400G DAC

• 800G OSFP DAC

AEC Solutions

• 400G AEC

• 800G AEC

AOC Solutions

• 400G AOC

• 800G AOC

Key advantages:

• High-speed product development capability

• Advanced signal integrity testing

• Reliable manufacturing quality

• Customized solutions for AI networks

C-LIGHT helps global customers build scalable, efficient, and future-ready AI data center networks.

8.Conclusion

DAC, AEC, and AOC each play an important role in modern AI data center infrastructure.

• DAC delivers the lowest cost and lowest latency for short connections.

• AEC provides improved signal integrity for high-speed AI clusters.

• AOC enables flexible and scalable optical connectivity.

With advanced 400G, 800G, and 1.6T interconnect solutions, C-LIGHT continues to support the evolution of next-generation AI data center networks.

9.DAC vs AOC vs AEC Q&A