High-speed DAC cables are made of silver-plated conductors and foam-insulated cores with pair shielding and total shielding. High-speed cable has excellent attenuation performance, low delay and anti-interference, and can realize high-frequency broadband transmission, with specifications of 30~24AWG and various structures such as 2P, 4P or 8P, which can be used in many different applications.
Generally, optical cables can be classified into direct attach copper cable and active optical cable (AOC). Direct-attach copper cable can either be passive or active, while AOC cable is always active.
What’s the difference between Active DAC and Passive DAC cables? The main difference is that Active DAC contains electronics for signal conditioning, and Passive DAC does not contain electronics for signal conditioning. Passive DAC cables are used when signal conditioning integrated into a port is provided by a switch. It costs less than Active DAC but has a higher upfront cost. Active DAC cables are used when signal conditioning integrated into a port is not provided by a switch. Active DAC generally costs more than Passive DAC, but the switch that comes with Active DAC costs less.
The advantages of DAC cable: why should we choose DAC over AOC?
Compare to the AOC(active optical cable), the high-speed DAC cable has five main benefits:
Higher data transmission rate:
current high-speed cables can support data transmission rates from 4Gbps to 10Gbps, which is higher than that supported by traditional copper cables. Moreover, the direct attach cable has high performance, is suitable for short-distance cabling in the data center, has a wide range of applications, and has strong switching ability of integrated schemes. Moreover, the DAC cable can scale to several meters, depending on the network speed, which is usually more than enough for interconnection within the data center. Whether connected between servers in a single rack or between switches in a cluster, DAC provides this function: reliable and affordable transmission with the highest available bandwidth.
with the development of copper technology, high-speed cables and optical fiber transceiver devices can be interchanged and hot swapped. One of the biggest advantages of DAC is reliability, which is measured in mean time between failures (MTBF). Passive copper cables have an MTBF of approximately 50,000,000 hours-typically an order of magnitude higher than the industry standard for fiber optic cables. DACs offer a major benefit to enterprise data centers where reliable data transmission is critical: avoiding downtime.
Good heat dissipation:
The high-speed cable is made of copper core, which has good heat dissipation effect, energy conservation and environmental protection.
The price of copper cable is much lower than that of optical fiber. The use of high-speed cable can greatly reduce the wiring cost of the whole data center. Generally speaking, the cost of passive copper cable is two to five times cheaper than that of optical cable of the same length. In addition, because the DAC does not consume power and its thermal design has low demand for cooling, it can greatly save the operating expenses of the data center.
Low power consumption:
low power consumption of high-speed cable. Since the passive cable does not need power supply, the power consumption of the active cable is generally about 440mW. If DAC copper cable is used instead of AOC optical cable, hundreds of kilowatts of power can be saved.
The advantages of high-speed cable has become the preferred solution for users in short-distance application scenarios. It is widely used in data center interconnection scenarios such as SATA storage devices, RADI system scenarios, core routers, 10G or 40G Ethernet.
But it also inevitably has some disadvantages:
- Short transmission distance, large weight, large volume and difficult to manage.
- Vulnerable to electromagnetic interference, such as poor response, degradation and other problems.
About AOC cable:
AOC is a communication cable that requires external energy to convert electrical signals into optical signals or optical signals into electrical signals during communication. Compare to direct attach cable, the active optical cable has lighter weight and can provide a greater and longer transmission reach up to 100-300m. However, the main defect of AOC active fiber cables is that it is a more expensive cabling assembly solution for high-density data center operators. Besides, AOCs are less durable if not managed properly.
To sum up, AOC optical cable has a longer transmission distance and reduces electromagnetic interference. Its advent has brought this misunderstanding: all aspects of the network should adopt this more novel technology. However, in the data center, it is often the wisest to use DAC copper cable, because DAC provides significant advantages in capital expenditure, operating expenditure, performance and reliability. And there are more choices of DAC direct attach cables in the market today, such as Aruba DAC cable, Cisco DAC cable, the various models of HPE DAC. In addition, DAC copper cable can support 100Gbps at a distance of up to 8 meters, which is ideal for data center deployment environment. At the same time, it provides lower delay, better reliability and lower power consumption, and the cost is much lower than that of optical cable.
In today’s data centers, more transmission capacity is should assistance using web server virtualization where numerous digital devices are incorporated on a solitary physical organize web server. To fit the ever-growing variety of OS (operating system) and applications staying on private web servers, virtualization needs substantially enhanced information transmission in between the web servers and buttons. At the exact same time, the quantity and sort of gadgets staying on the network has actually substantially enhanced the quantity of information that should be sent to and from storage area networks (SANs) and Network Attached Storage (NAS). The application is generally for broadband I/O applications in storage space, networking and telecommunications markets, Switches, servers, routers, network interface cards (NICs), Host Bus Adapters (HBAs), High Density and High Data Throughput. All in all, the direct attach cables providing a cost effective solution that support multiple protocols including 40GbE, 100GbE, Gigabit&10G Ethernet, 8G FC, FCoE, and InfiniBand.