What is the difference between 100GQSFP28PSM4 optical module and QSFP28CWDM4 optical module?

The 100GQSFP28 optical module is an optical module that can be used to support 100G transmission, and it can also be said to be a new type of solution. The cost and power consumption of the data center is one of the important factors that its builders need to consider, which is also an important driving force for the development of the optical communications market. Looking back at the development history of 100G optical modules, the development and improvement of its packaging styles (CFP, CFP2, CFP4) and standards are also mainly centered on two aspects of low cost and low power consumption. In the market, there are many 100GQSFP28 optical modules, but in this article, Gigalight Communications introduces two 100GQSFP28 optical modules-100GQSFP28PSM4 optical modules and QSFP28CWDM4 optical modules. What is the difference between the two?

First of all, let’s first understand the advantages of 100GQSFP28 optical module:

1: Port density

The first generation of 100G optical modules was a very large CFP optical module, and then CFP2 and CFP4 optical modules appeared. Among them, the CFP4 optical module is the latest generation of 100G optical modules, and its width is only 1/4 of the CFP optical module. The packaging style of the QSFP28 optical module is smaller than that of the CFP4 optical module, which means that the QSFP28 optical module has a higher port density on the switch.

2: Power consumption

The power consumption of the QSFP28 optical module is usually no more than 3.5W, while the power consumption of other 100G optical modules is usually between 6W and 24W. From this point of view, the power consumption of QSFP28 optical modules is much lower than other 100G optical modules.

3: Cost

The current data center is mainly a 10G network architecture, and its interconnection solutions are mainly 10GBASE-SR optical modules and duplex LC multimode fiber jumpers. If you directly upgrade to a 40/100G network based on the existing 10G network architecture, Will save a lot of time and cost.

What is the difference between 100GQSFP28PSM4 optical module and QSFP28CWDM4 optical module?

1: Overview of 100GQSFP28PSM4 optical module


1: QSFP28PSM4 optical module is a high-speed, low-power product, with a hot-swappable QSFP appearance, built-in digital diagnostic function, and 8 optical fibers, each with a data rate of 25Gbps;

2: QSFP28PSM4 optical module adopts 12-channel MTP interface, and realizes 8-channel optical fiber bidirectional 100G transmission at the same time;

3: Although the QSFP28PSM4 optical module runs in a single-mode fiber, its wiring structure is the same as that of the QSFP28SR4 optical module. Without changing the existing wiring structure, using the QSFP28PSM4 optical module can save the conversion cost between multi-mode and single-mode.

4: The working principle of QSFP28PSM4 optical module is almost the same as that of QSFP28SR4 optical module. The difference is that the QSFP28PSM4 optical module operates on single-mode fiber, while the QSFP28SR4 optical module operates on OM4 multimode fiber.

2: Overview of QSFP28CWDM4 optical module
100GCWDM4 is also a multi-source agreement (MSA). The 100GCWDM4 optical module introduces WDM technology and adopts a duplex LC interface. When used with a single-mode fiber, the transmission distance can reach 2km.

The transmission rate of 100GQSFP28CWDM4 optical module is 103.1Gbp, which is mainly used in computing, high-frequency trading and other fields. Its cost is significantly higher than QSFP28PSM4 optical module. Through coarse wavelength division multiplexing (CWDM) technology, the QSFP28CWDM4 optical module multiplexes four wavelengths of 1270nm, 1290nm, 1310nm and 1330nm onto a single-mode optical fiber for transmission.

[Optical Module Package]

The optical module package used by the 100GQSFP28CWDM4 optical module is QSFP28, which is an optical module that can be used to support 100G transmission. It provides an ideal solution to the current needs of ultra-large data centers to increase the transmission rate. The package size of the QSFP28 optical module is larger than that of the CFP4 The optical module is smaller, which means that the QSFP28 optical module has a higher port density on the **.

【Digital diagnosis function】

The 100GQSFP28CWDM4 optical module has a built-in digital diagnostic function, which can effectively monitor important performance parameters such as the optical module’s transmit optical power, received optical power, temperature, supply voltage, laser bias current, and warning messages.


The 100GQSFP28CWDM4 optical module can be directly upgraded from 25G to 100G without 40G, which greatly reduces the cost of the wiring system.