10G DAC vs AOC: Choosing the Best Option for Your Network

10G DAC and 10G AOC are two popular high-speed cabling solutions utilized in data centers. This article will offer a comprehensive overview of SFP+ DAC cables and 10G AOC cables, including a comparison of their features.

Overview of 10G SFP+ DAC and 10G AOC

The 10G SFP+ DAC (Direct Attach Copper) cable features a dual-core copper design with SFP+ connectors on both ends, allowing direct connections to active devices. Both Passive and Active SFP+ DAC can transmit electrical signals over copper wire; however, passive 10G SFP+ DAC transmits without signal modulation, while Active SFP+ DAC includes built-in electronics in the optical transceiver to enhance the signal. Typically, 10G SFP+ DAC cables are used to connect switches, servers, and storage devices within cabling racks.

In contrast, the 10G AOC (Active Optical Cable) comprises multi-mode fiber optic patch cords with SFP+ connectors at each end. This cable requires external power to facilitate the conversion of optical and electrical signals, first converting electrical signals to optical, then back to electrical. Similar to 10G SFP+ DAC cables, 10G AOC cables are primarily used for interconnecting storage devices, switches, and servers within data center cabling racks.

Key Differences between 10G DAC and AOC

While 10G DAC and AOC cables are both popular choices for data networking, particularly for high-speed and high-reliability interconnections in data centers, high-performance computing, and large-capacity storage devices, it's important to recognize their differences.

10G DAC vs AOC: Power Consumption

The 10G SFP+ DAC high-speed cable is more compact than the 10G AOC cable. Typically, a 10G AOC cable consumes less than 1W, which is still higher than the power usage of a 10G DAC cable that generally consumes under 0.1W due to its efficient thermal design, leading to nearly zero power consumption. Therefore, opting for an SFP+ DAC high-speed cable solution can significantly reduce operating costs associated with power consumption.

10G DAC vs AOC: Transmission Distance

The 10G AOC cable supports longer transmission distances than the 10G SFP+ DAC high-speed cable. Utilizing fiber optic technology, the 10G AOC can reach a maximum distance of 100 meters, whereas the 10G SFP+ DAC cable has a maximum distance of 10 meters (with passive DAC at 7 meters and active DAC at 10 meters). It's important to note that the maximum transmission distance for DAC cables can vary based on the data rate; for instance, a 100G DAC cable may only transmit up to 5 meters. This limitation highlights the typical use of SFP+ DAC cables, which are often employed for connecting devices within the same rack, such as linking a server to a TOR switch. In summary, SFP+ DAC high-speed cables are ideal for short-distance connections, while AOC cables are suited for longer network links.

10G DAC vs AOC: Cost

The 10G SFP+ DAC high-speed cable is more affordable than the 10G AOC cable. This is because the SFP+ DAC cable has fewer internal components, simpler construction, and utilizes cheaper copper instead of fiber. Thus, when deploying a network in a large data center, using a significant number of DAC cables can lead to substantial savings compared to AOC cables. For short-distance transmissions, the 10G DAC cable offers a more cost-effective solution; however, for longer distances, a comprehensive cost comparison of both options is necessary.

10G DAC vs AOC: Durability

The 10G SFP+ DAC cable, constructed from sturdy copper, is generally more robust than the 10G AOC cable, which is made from fiber optics and can be more vulnerable to damage if mishandled. Both types of cables have an operating temperature range of 0-70°C. While passive SFP+ DAC cables consume very little power and generate minimal heat, allowing them to perform reliably within this range, AOC cables offer increased flexibility, which can enhance airflow for cooling. However, the inherent durability of DAC cables makes them a more resilient choice in demanding environments.

10G DAC vs AOC: Reliability

The 10G AOC cable offers superior resistance to electromagnetic interference (EMI) compared to the 10G SFP+ DAC high-speed cable. EMI refers to disturbances caused by external power sources affecting electrical circuits. As noted earlier, 10G AOC cables utilize optical fiber, a dielectric material that does not conduct electricity, making them immune to EMI and suitable for various applications. In contrast, 10G SFP+ DAC cables use copper, which is prone to EMI due to its capacity to transmit electrical signals. To prevent issues like system crashes and failures, it is essential to consider the EMI environment when using these cables.

Practical Use Cases for 10G SFP+ DAC and AOC Connectivity

Use Cases for FS 10G SFP+ DAC and AOC

The 10G DAC cable is designed to connect switches or servers within the same rack or adjacent racks, such as linking 10G ToR switches to server racks. With a maximum length of 10 meters, it offers a cost-effective solution with low power consumption and minimal latency, making it perfect for short-distance connections. While ideal for high-density ToR setups, it can make centralized maintenance more challenging.

In contrast, the 10G AOC cable is suited for data center applications like ToR, EoR, and MoR. It connects ToR switches across the network and server racks over distances of up to 70 meters. In EoR configurations, it consolidates multiple server connections into network cabinets, streamlining maintenance, though cable management may become complex. The MoR setup follows a similar principle, improving connection simplicity and management.

Recommended Connectivity Solutions for 10G SFP+ DAC and AOC

FS 10G SFP+ DAC and AOC provide efficient, high-performance connectivity for various network configurations. Both cables share the same basic connection method, but it's essential to ensure that the switches and network interface cards (NICs) support SFP+ ports for seamless 10G data transmission. This is because both DAC and AOC use SFP+ physical interfaces, regardless of their different transmission mediums (copper for DAC and optical fiber for AOC). For instance, the SFP-10G-PC01 model represents a typical 10G SFP+ DAC cable, ideal for short-distance connections within data centers where low cost and low latency are priorities. In contrast, the SFP-10G-AO01 model exemplifies a 10G AOC cable, which is better suited for longer distances or more flexible installations.

A common setup involves directly connecting 10G switches for stable, high-speed communication.

Another typical configuration includes connecting switches to server NICs, such as in leaf-spine architectures, ensuring efficient data transmission across network devices and improving scalability in modern data centers.

Choosing the Right Cable for Your Network

In summary, choosing a 10G network deployment solution requires careful consideration of factors such as the application environment, cabling space, distance requirements, power consumption constraints, and budget. For transmission distances up to 10 meters, where power consumption is limited and cost is a priority, 10G SFP+ DAC cables are ideal. Conversely, in data centers or environments with distances up to 70 meters and high EMI, 10G AOC active optical cables are the better option.