SFP vs SFP+ vs QSFP: What’s the difference?
What is an SFP?
SFP is a packaging form of optical modules, and its full name is small hot-swappable optical transceiver integrated module. The SFP optical module is currently the smallest pluggable optical module, and each 1U panel can support up to 48 SFP ports. The SFP optical module contains one channel of transmission and one channel of reception, supporting full-duplex mode.
What Is the SFP+ Module?
The SFP+ optical module is an enhanced version of SFP. It has a higher transmission rate and can support up to 16Gb/s. It has the same appearance size as SFP and is backward compatible with SFP.
SFP vs SFP+
SFP+ vs. SFP Modules: Data Rates and Distances
SFP+ transmission rates can be divided into 8.5G, 10G, and 16G according to different applications;
SFP transmission rate supports 155M, 622M, 1.25G, 2.5G and 4.25G.
The communication distance of SFP+ SR/LR/ER/ZR is 300m/10km/40km/80km respectively;
The transmission distance of SFP SX/LX/EX/ZX is 500m/10km/40mk/80km respectively.
SFP+ vs. SFP Modules: Form Factor and Power Consumption
The appearance dimensions of SFP+ and SFP are the same, and SFP+ is backward compatible with SFP.
SFP+ is related to the power consumption and module type of SFP. The farther the distance, the higher the power consumption.
The power consumption of SFP+ SR/LR is less than 1W in the full temperature range, the power consumption of SFP+ ER is less than 1.5W, and the power consumption of SFP+ ZR is less than 2W;
The power consumption of SFP SX/LX/EX is less than 1W in the full temperature range, and the power consumption of SFP+ ZX is less than 1W. Consumption is less than 1.5W.
SFP+ vs. SFP Modules: Common Applications
SFP+ is mainly used in large-capacity and long-distance networks such as 10G Ethernet, data centers, metropolitan area networks, and OTN backbone networks; SFP is mainly used in small local area networks such as wireless base stations, campus networks, and internal enterprises.
GBIC vs SFP
GBIC is the earliest form of optical module packaging. The optical and electrical interface is separately packaged as a pluggable module, which is independent from the motherboard, making the optical communication system better scalable and maintainable. GBIC communication rate supports up to 1.25Gb/s, and its size and power consumption are relatively large. The size of SFP is reduced by half compared to GBIC.
Compared with GBIC, the size of SFP is reduced by half, the maximum rate is increased by 4 times, and the communication rate of the entire device is increased by 8 times. SFP also supports rate selection control function. In low-speed mode, by controlling the bandwidth of the module, higher sensitivity and longer transmission distance can be obtained.
What is a QSFP Port?
SFP and QSFP both refer to common ports on switches or servers. Each QSFP Port contains 4 signal channels, so it is called Quad SFP. QSFP port size is slightly larger than SFP, and port density is lower than SFP. Under the same single channel rate, QSFP communication rate is 4 times higher than SFP. The internal transceiver and receiver of the QSFP module can integrate WDM functions to ensure large-capacity transmission while also reducing the complexity of the network.
How to Choose SFP Transceivers?
Speed and Bandwidth Requirements:
First we need to know the host interface type and communication rate,. The available rates for the SFP module are 155M, 622M, 1.25G, 2.5G and 4.25G. If the host has a higher rate, you need to choose the SFP+ module, which can support 8.5G. 10G and 16G.
Fiber Type and Distance:
Secondly, select the module type according to the transmission distance, segmented according to 500m/10km/40km/80km. Within these ranges, there are corresponding standard modules to choose from. If the transmission distance is less than 500m, you can choose multi-mode modules and multi-mode optical fibers to reduce costs.
Compatibility:
Compatibility is also an important factor to consider. Choose the appropriate module according to the brand and model of the switch/server.
First, the compatibility issue between modules and switches/servers requires the selection of certified optical module brands and models based on the switches/servers.
Second, wavelength matching. Optical communication has three wavelength windows, and WDM technology is also used in each wavelength window to make the division of wavelengths more precise. The wavelengths transmitted and received by the optical module must match the module at the opposite end for normal use.
Environmental Considerations:
Our products are RoHS-10 compliant and lead-free，and have Excellent EMI performance.
Budget:
According to the above option guidance, choose the appropriate optical module. Do not have too much redundancy in the selection of communication rate and transmission distance. You can choose easy-to-use and cheap modules to meet budget requirements.
Conclusion
SFP and SFP+ are similar, but are quite different from QSFP. It is necessary to consider the host port type, transmission distance, fiber or cable type, cost and other factors to select the appropriate optical module.
FAQ
Is QSFP the same as SFP+?
QSFP and SFP+ are both pluggable optical modules, but they are two completely different types of optical modules and are not compatible in structure and electrical interface.
Will a SFP+ work in a SFP slot?
SFP+ is backward compatible with SFP. If the rates match, SFP+ can work normally on the SFP slot.
Can you plug SFP into QSFP?
No, the structural dimensions and electrical interfaces of QSFP and SFP+ are different, and the SFP module cannot be inserted into the QSFP slot.
Is QSFP+ backwards compatible with SFP+?
No, QSFP+ and SFP+ are two different series and are not compatible.
Is SFP and SFP+ backwards compatible?
SFP+ is backward compatible with SFP. If the rates match, SFP+ can work normally on the SFP slot.
Is SFP only for fiber?
SFP media ports include optical fiber and RJ45, which can be selected according to the use environment.
Can I plug Ethernet into SFP+?
Yes, you need to use an SFP+ module that supports RJ45 interface.
Which is better Ethernet SFP or FC SFP?
This needs to be selected based on the actual application environment. If the opposite end uses an optical interface, then FC SFP is a better choice; if the opposite end uses a network port, you can choose Ethernet SFP.
Can you use Fibre Channel SFP for Ethernet?
The communication rates of Fiber Channel and Ethernet are different. It needs to be checked whether the SFP module supports both rates at the same time.
