When choosing the right direct attach cable (DAC) or active optical cable (AOC), it can be difficult to decide which is best for you. Both have their own unique benefits and drawbacks, so how do you know which one is right for your needs? In this blog post, we will compare and contrast DACs and AOCs, and help you decide which one is right for you.
What are DAC and AOC?
The DAC cable adopts the integrated design of the module connector and the copper core cable, which is an ideal solution for short-distance transmission within the cabinet or between cabinets. Taking the 10G network as an example, the interconnection of the 10G SFP+ ports in the equipment adopts the 10G DAC cable. The cost performance of the cable is the highest, and the purchase cost can be minimized without affecting the transmission performance.
DAC cables are often used in short-distance wiring schemes in data centers. Compared with other AOC active optical cables and optical module transmission schemes, their advantages are higher cost performance, but the short transmission distance is its limitation. If the distance between devices exceeds the length of the cable, it is necessary to choose AOC active optical cable and optical module solution.
The following table compares the important parameters of DAC and AOC:
| Cable Type | Transmission Media | Wire Diameter | Transmission Distance | Power Consumption | Cost |
| Passive DAC | Copper wire | Thick | Short (≤ 10m) | Low | Low |
| Active DAC | Copper wire | Medium | Medium (≤ 15m) | Medium | Medium |
| AOC | Fiber cable | Thin | Long (≤ 30m) | High | High |
How to choose between DAC cable and AOC cable
The difference and connection between AOC and DAC were introduced earlier. How to choose which product to use in practical application?
The DAC has low cost and low power consumption, but the transmission distance is short. It is mainly concentrated in the application scenarios of 1 meter to 5 meters. The product structure is simple, the parts are few, and the reliability is high. It is suitable for short-distance applications that require low cost and low power consumption.
AOC has a long transmission distance, and the common length ranges from 1 meter to 30 meters. However, AOC products with a length of more than 300 meters can also be customized, but the cost is high and the power consumption is high, which is suitable for scenarios requiring convenient wiring or long transmission distance.
Active DAC is generally used in application scenarios of 5-10 meters. Since the cost of copper cable is much higher than that of optical cable, the cost of optical devices is rapidly decreasing. In the distance range of 5-10 meters, the price of active DAC products Compared with AOC products, there is no obvious advantage, but the active DAC will be bulkier in use, and the heavyweight will lead to a lot higher transportation costs, so the market share is much smaller than that of passive DACs and active optical cables.
