10G DAC vs 25G DAC vs 40G DAC vs 100G DAC
Table of Contents
10G SFP+ DAC cable
10G DAC high-speed cable is composed of copper cable and two SFP+ connectors. Unlike SFP+ optical modules, it does not have optical lasers and electronic originals, and transmits electrical signals through copper cable, without the process of photoelectric conversion. 10G SFP+ DAC is a copper cable with SFP+ connectors designed at both ends, using 10G SFP+ DAC cabling is more flexible, and the transmission distance can reach 15 meters, which is less difficult to operate in the actual construction process. Moreover, 10G SFP+ DAC cabling saves connection equipment, no need to use patch panels, servers and network equipment can be directly connected to TOR switches, which indirectly saves input costs.
There are two types of SFP+ direct attach copper cables, SFP+ active copper cable (ACC) and SFP+ passive copper cable (PCC). SFP+ passive copper cable has no signal amplification in the cable assembly. While the SFP+ active copper cable (ACC) has signal amplification and equalization in the cable assembly. SFP+ ACC assemblies are typically used in host systems that do not employ EDC. The picture below shows an HPE J9283B compatible 10G SFP+ passive direct attach copper cable.
10G SFP+ DAC high-speed cables are widely used for interconnection between 10G fiber NICs, interconnection between 10G ToR switches and servers, and stacking of 10G Ethernet switches, etc. 10G SFP+ DACs are characterized by low loss, energy efficiency and low cost, and can meet the growing cabling needs for transmission rate, scalability and reliability. For connectivity between servers and switches within 10m, 10G SFP+ DACs are recommended.
25G SFP28 DAC cable
25G technology is the basis for the 100G (4*25Gbps) Ethernet standard. 25G high-speed cable consists of a copper cable and fiber optic transceiver units at both ends, which uses connectors similar to the interfaces of optical modules, but the connector modules on top of the high-speed cable do not have expensive lasers, thus greatly reducing the cost of short-haul applications.
There are two types of 25G high-speed cables: 25G SFP28 to SFP28 DAC and 100G QSFP28 to 4xSFP28 DAC. 25G SFP28 to SFP28 DAC is a very cost-effective solution for short-haul link transmission, which can establish a 25G link through the SFP28 port of the switch.
25G technology is very promising as it can provide higher port densities compared to 40G technology, while also reducing costs. Currently, with a strong push from the 25G Ethernet Alliance, cloud computing giants such as Microsoft and Google have proposed 25G and 50G Ethernet solutions. In addition, according to Dell’Oro, the next generation of servers will reach 25Gbps, which means that more devices will choose 25G SFP28 DACs as the best network solution.
40G QSFP+ DAC cable
40G DAC cables with QSFP+ connectors on both ends, typically used to connect switches, routers and servers. 40G DAC cables have a maximum transmission distance of 15 meters and can meet the short-range connectivity needs of emerging data centers and high-performance cloud computing applications. Common types can be classified as 40G QSFP+ to QSFP+ DAC and 40G QSFP+ to 4xSFP+ DAC.
- 40G QSFP+ to QSFP+ DAC
The 40G QSFP+ to QSFP+ DAC is pre-terminated with QSFP+ connectors at both ends and is suitable for connecting two 40G network devices with a maximum transmission distance of up to 7m. The transmission distance of passive direct attach cable is generally less than 7m, while the active DAC cable is longer, depending on the manufacturer.
40G QSFP+ to 4xSFP+ DAC
The 40G QSFP+ to 4xSFP+ DAC is pre-terminated with QSFP+ connectors at one end and four 10G SFP+ connectors at the other end to connect 40G devices and 10G devices, suitable for 10G and 40G network connections with a maximum transmission distance of 7m. Fiber Mall provides 40G QSFP+ DAC high-speed cables to meet users’ needs for 40G network construction needs.
100G QSFP28 DAC cable
The 100G optical module is born to adapt to the development trend of network market from 10G to 40G and 100G. The transmission rate is 100G, which plays a vital role in building 100G network system.
QSFP28 is applicable to 4x25GE access port. It uses four optical channels to transmit data, and the maximum transmission rate of each optical channel of the optical module can reach 28Gbps. It is mainly used for 100G transmission applications.
100G QSFP28 DAC, 100G QSFP28 to 4xSFP28 DAC and 100G QSFP28 AOC can be used for the connection between server and switch, storage and switch, and switch to switch. The link length of 100G QSFP28 DAC and 100G QSFP28 to 4xSFP28 DAC is relatively short, and their ideal application range is within 5m.
- 100G QSFP28 to QSFP28 DAC
100G QSFP28 to QSFP28 DAC high-speed cable is suitable for stacking, cascading and direct connection between 100G devices in short distance, such as 100G switches. It can provide customers with 100G high bandwidth data interconnection capability, provide 4-way duplex channels, the working rate of each channel can support up to 25Gb/s, and the aggregation bandwidth is 100GB/s. It complies with SFF-8436 specification and is applied to the connection between QSFP28 port devices, and it supports the distance range of 1m-5m, such as QSFP-100G-CU1M.
- 100G QSFP28 to 4xSFP28 DAC
100G QSFP28 to 4xSFP28 DAC high-speed cable is applicable to the interconnection between 100G and 25G equipment. One end is 100G QSFP28 interface and the other end is four 25G SFP28 interfaces, which can provide customers with 100G high bandwidth data interconnection capability. It complies with SFF-8665/SFF-8679, IEEE 802.3bj and Infiniband EDR standards, and supports the distance range of 1m-5m. It is widely used in data center or Supercomputer Center system scenarios.
In conclusion, as a low-cost short-distance connection scheme to replace the optical module, whether 10G, 25G, 40G or 100G DAC high-speed cables can greatly save cost and power consumption in short-distance applications, because the connector module on the DAC copper cable does not have expensive optical lasers and other electronic components. With higher Ethernet speed, cloud computing, Internet of things and virtual data center all put forward more requirements for data center operators, the data speed of the data center has actually moved towards 400G, Therefore, in addition to connections within 3-5m in the server, DAC can also be used (special insulating materials are required for 5-7m to meet the characteristic requirements). Connections beyond 3-5m distances are generally realized through AOC(active optical cable), and the wiring cost of using AOC is higher.