What’s the difference between 10GBASE-T, SFP + , DAC?

- Dec 21, 2020-

Overview of 10GBASE-T Copper Transceivers, SFP + Optical Transceivers, SFP + high-speed cable

The 10GBASE-T SFP + Copper transceivers is designed for high-speed communication links over 10Gb Ethernet and can be transmitted over CAT 6A/7 network lines. It is the first 10G transceivers to provide 10Gb/S through Ethernet copper cable and meets the SFF-8431 and SFF-8432 MSA standards.

10GbE SFP + optical transceivers can also be used for 10G network transmission, the maximum transmission distance is 100km. It comes in many models, such as 10GBASE-SR, 10GBASE-LR, 10GBASE-ER, 10GBASE-ZR, etc. .

For SFP + DAC high-speed cables, it uses 10GbE copper cables as active or passive dual coaxial cable assemblies, with SFP + connectors at both ends, enabling 10G short-haul connections. As a result, SFP + high-speed cables are commonly used for Tor switch stack connections, as well as for short-distance connections between switch ports and Ethernet interfaces on server and rack storage devices.

What’s the difference between 10GBASE-T copper, SFP + optical and SFP + DAC high-speed cables?

Flexibility & Backward compatibility

The 10GBASE-T copper transceivers uses the interoperable 10GBASE-T technology, which uses RJ45 connectors and can be automatically negotiated between 10/100/1000Mbps and 10G rates. In other words, the 10GBASE-T copper transceivers is backward compatible with standard copper cable network equipment. The 10GbE SFP + optical transceivers can be used in 10G Ethernet and 10G Fiber Channel, but is not compatible with a copper cabling system, although it can sometimes be used in 1G fiber networks. As for the SFP + DAC High Speed Cable, it is not compatible with existing Gigabit Ethernet and is only used for connections to 10G Ethernet switches.

Delay

With increased usage of private cloud applications, the need for low latency in large data centers is growing rapidly. Low latency is critical to ensuring fast response times and reducing CPU idle cycles, which can improve data center efficiency and ROI. The 10GBASE-T Copper Transceivers uses the PHY standard, which allows data to be transmitted over copper cables without error using block coding. The standard defines the 10GBASE-T copper transceivers as having a transceiver time of 2.6 microseconds. The SFP + Fiber uses a simplified electronic device that is not coded and has a delay time of about 300 nanoseconds per link. As can be seen from the table below, the delay of SFP + fiber is lower than that of the other two products.

Transmission distance

The maximum transmission distance of 10GBASE-T transceivers on Cat6a or Cat7 is 100 meters, and the maximum transmission distance of 10GbE SFP + transceivers on single mode fiber is 100 kilometers. However, the SFP + DAC high-speed cable can only transmit up to 10 meters, which is suitable for the wiring connection between the chassis and the chassis. If transmission distance is not a factor to be considered, SFP + DAC high-speed cable with lower power consumption and lower delay is an ideal routing solution for data center routing.

Cost

10GBASE-T RJ45 transceivers are typically cabled using CAT6A or CAT7 network cables, which is less expensive than 10GbE SFP + optical cabling. In a data center, hundreds of cables are often needed, and using cheap Internet cable can save a lot of money. In addition, the 10GBASE-T copper transceivers can maximize the use of the existing copper cable structure wiring, but also save a lot of costs. 10G SFP + optical transceivers require relatively expensive single-mode or multimode fiber jumpers to transmit, and fiber cabling systems are expensive to maintain. The SFP + DAC high-speed cable is the cheapest of the three, with the only drawback being the limited range.

10GBASE-T Copper Transceivers, SFP + Optical Transceivers, SFP + DAC high-speed cable application scenario


10GBASE-T copper, 10GbE SFP + optical and SFP + DAC high-speed cables can all be used for 10G Ethernet transmission, but they have different application scenarios in data centers and Enterprise Networks. The 10GBASE-T SFP + Copper transceivers is commonly used to transmit cabling connections to the data centers and Enterprise Networks of the Rack Top (Tor) , Mor, Eor within a distance of 30 meters. 10G SFP + optical transceivers are commonly used in data centers on the Tor, Mor, Eor backbone core network, with a maximum transmission distance of 100 km. For SFP + DAC high-speed cables, these are typically used for server-to-rack or intra-rack wiring connections to Tor switches, usually within a distance of 10 meters, such as interconnections between switches on top of the rack and servers or storage devices.

Conclusion
All in all, the 10GBASE-T Copper Transceivers, the SFP + Optical Transceivers, and the SFP + DAC high speed cable differ in flexibility, Backward compatibility, distance, application latency, and cost. You can choose the right product based on your network needs. It is worth noting that with the popularity of optical fiber cabling system, copper cabling system will gradually withdraw from the market, therefore, 10GBASE-T copper transceivers will gradually withdraw from the market. With the decrease of price and power consumption, 10GbE SFP + optical transceivers will be an ideal solution for data center network.