What Is a DAC Cable? Direct Attached Cables Guide

DAC cables running out of a server

There’s a reason why the job outlook for cable line installers is expected to increase by 6% over the next decade. Data centers rely on cables to communicate necessary electronic signals with each other. 

If you work with data centers, you’ve likely encountered two terms before AOC cables and DAC cables. Despite this fact, many people are unfamiliar with direct attached cables compared to AOC. So what is a DAC cable? 

And what are the specific types of benefits that come with installing them? People who want to discover the answer to these questions are in the right place. This helpful article will walk you through everything you need about this critical data center tool. 

What Is a DAC Cable?

DAC stands for direct attached cables. This is a copper cable that allows devices to chat with each other by both sending and receiving signals. 

This copper is covered in electromagnetic shielding and has connectors attached to each end. DAC cable has a fixed length that doesn’t travel long. As such, it’s best suited for short-length connections. 

Passive vs. Active DAC Cables

DAC’s counterpart, the AOC cable, can only be active, which means it uses power. However, that’s not the case with DAC cables. These cables can be both active and passive, which gives you more options. Passive DAC cables are ideal because they use much less power. 

However, in some cases, it might be appropriate to have active DAC cables. For example, get a little more distance at the expense of some power usage; then action would be a good call for your needs. 

Want to know the difference between fiber optics and copper cabling? Explore this article to discover everything you need to know. 

A server room in a data center

Benefits of DAC Cables

You might think that AOC cables are the clear superior. But the reality is that DAC cables have plenty of benefits to keep in mind. In this section, we’ll discuss each of them in more detail. 

Higher Transmission Rates

Data transmission rates can be determined by various factors, including the complexity of the technology being used. In this way, DACs have a clear benefit. The simple nature of the design means that they can transmit at a rate between four to ten gigabytes per second. 

This is far higher than other copper wires. Just keep in mind that this high bandwidth does come at a cost: it must be short-distance connections. But as long as it’s used for this application, then it ultimately makes sense. 

Better Interchangeability

What if you decide that fiber optic cabling is the better solution for your needs down the line? No problem! DAC cables are interchangeable, so you can easily upgrade them whenever needed. 

Better Heat Dissipation

The copper material in DAC cables helps dissipate much of the heat that runs through them. This makes your data center both safer and more environmentally friendly. 


The cost of copper wire is exceptionally cheap. This is especially true when you compare it to more expensive technology like fiber optic cables. So how much more affordable is it? It can depend, but most of the time, DAC can be up to five times cheaper. 

On top of that, DACs use little to no power. That means your power bill will also be more affordable. As such, it’s a great option for data centers on a budget for their infrastructure. 

Lower Power Consumption

Data centers consume ten to fifty times the amount of power in terms of floor space as commercial office buildings do. As such, many data centers are prioritizing low power consumption.

Luckily, DAC cables are perfect for this. Unlike AOC cables, DAC does not require a power source; as such, you can save thousands on your power bill at the end of every month. If you want to discover more about the power consumption of data centers, explore this resource here

Related: Data Integration Architecture for Smart Buildings

How Far Do Direct Attached Cables Reach?

The specific length that a DAC can reach will ultimately depend on the particular type of cable you’re using and the person installing it. 

However, these days direct attached cables don’t usually exceed five meters in reach. If the space of a line is a problem for you, then consult this guide. It will walk you through breaking cable reach limitations. 

Related: IT Cooling is Evolving for the Modern Data Center Demands

How to Get DAC Cables 

The best way to install DAC cables is to get in touch with a provider that knows their way around it. Ideally, they’ll inspect your current set-up to determine your cabling needs. From there, they can recommend a DAC cabling solution that works best for your needs, whether that’s active or passive. 

In some cases, they might suggest that AOC better fits your needs. Just make sure that they’re experienced and knowledgeable. Otherwise, they might just be trying to upsell you. 

Do you believe that DAC cables are suitable for your needs? If so, contact C&C Technology today so we can help you start setting things up. 

Close up of ethernet cable

The Importance of DAC Cables

DAC cables are commonly misunderstood when it comes to data centers. There’s a misconception that AOC optical cables are the more novel technology. As such, any network that doesn’t adopt them is inherently flawed. 

But this simply isn’t true. The reality is that there’s a time and a place for DAC cables. In fact, if set up correctly, it can often be a more cost-effective solution for your data center

So make sure you don’t rule them out. Discuss DAC cables with your installer today to see whether or not it’s the right option for your needs. 

Related: How to Test Fiber Optic Cable: Best Method & Tools

Last Updated on June 8, 2023 by Josh Mahan

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