Especially within data centers, there is a significant demand for interconnections both within and between racks. DAC cables not only meet the need for high-speed interconnects but also consume virtually no power and generate no heat, thereby reducing the load on cooling systems. Compared to optical modules, DAC cables are cost-effective, have a lower failure rate, and are the most cost-efficient interconnect solution for data centers.

DAC Advantages:

High Performance: Capable of transmitting data at speeds of 10Gbps, 25Gbps, 40Gbps, 50Gbps, and 100Gbps, making it ideal for short-distance cabling in data centers.

Energy Efficient: Made of copper, which provides excellent heat dissipation and energy savings.

Low Power Consumption: Passive cables consume no power, while active optical cables typically consume around 440mW.

Cost-Effective: Significantly cheaper than the combination of fiber optics and optical modules.

DAC Disdavantages:

Short Transmission Distance, Heavy, Bulky, and Difficult to Manage;

Susceptible to Electromagnetic Interference

Passive DAC & Active DAC

DAC cables are classified into two types: active and passive. Active DAC cables have built-in amplifiers and equalizers to enhance signal quality, though they come at a higher cost. Typically, when the transmission distance is less than 5 meters, passive DAC cables are preferred. For distances greater than 5 meters, active DAC cables are recommended to ensure signal integrity.

The connectors on DAC cables are the same as those used in optical modules, making them an ideal choice for short-distance cabling within a rack in Top-of-Rack (TOR) scenarios. In End-of-Row (EOR) scenarios, DAC copper cables can also be used effectively if the transmission distance is less than 10 meters.

DAC cables use the same interface types as optical modules

Direct Attach Cable Vs. Active Optical Cable

Power Consumption: The maximum power consumption of AOC (Active Optical Cable) is lower than that of DAC (Direct Attach Cable).

Transmission Distance: AOC (OM3) typically supports transmission distances of up to 100 meters, whereas DAC cables generally support distances of around 7 meters.

Transmission Medium: AOC uses optical fiber, which is immune to electromagnetic interference, while DAC uses copper, which can be affected by electromagnetic interference.

Transmission Signal: AOC transmits optical signals, whereas DAC transmits low-voltage pulse signals.

Cost: AOC is significantly more expensive than DAC.

Size and Weight: At the same length, AOC weighs about a quarter of what DAC weighs and has approximately half the volume of DAC.

Transmission Performance: AOC has a lower bit error rate compared to DAC, offering better transmission reliability and performance.