SFP28 vs SFP+ Transceiver, What is the Difference?

SFP28 vs SFP+

In the realm of data center networks, SFP28 and SFP+ transceivers reign as two commonly utilized modules. Both play a crucial role in data transfer applications. However, despite their shared features, they diverge significantly in terms of speed, distance, power usage, compatibility, cost, availability, and more.

This article delves into the specifics of SFP+ and SFP28 transceivers, highlighting their defining differences. From definitions and working principles to applications, and frequently asked questions, we present a comprehensive guide. Stay tuned for a comprehensive exploration of SFP28 and SFP+ transceivers.

What is SFP28?

SFP28, or Small Form-Factor Pluggable 28, represents the third evolution of SFP interconnect systems tailored for 25G performance based on the IEEE 802.3by specification (25GBASE-CR). This encompassing portfolio encompasses the SFP28 transceiver, SFP28 DAC, SFP28 AOC, and SFP28 ports.

With a maximum transmission rate of 28Gbps, the name SFP28 reflects its capabilities. In essence, SFP28 serves as an upgraded iteration of SFP+, specifically optimized for 25G connectivity. It maintains the familiar SFP+ form factor while supporting 25Gbps to 28Gbps electrical interfaces per channel.

What is SFP+?

SFP+ stands as an advancement over the standard SFP, catering to higher data rates of 8G/10G/16G. Its specifications are outlined in the SFF-8431 standard. This comprehensive range encompasses SFP+ transceivers, SFP+ DAC, SFP+ AOC, and SFP+ ports.

For instance, considering the SFP+ transceiver, it finds utility in various scenarios. It commonly supports 8G or 16G Fibre Channel, 10G Ethernet, and SDH/SONET STM64 applications. Notably smaller than the prior 10G XENPAK and XFP modules, SFP+ offers almost double the port density, establishing itself as the preeminent choice for 10G transceivers in the market.

SFP28 vs SFP+, What is the difference?

Data Rate Distinction Between SFP+ and SFP28

SFP+ transceivers are tailored for 10G operations, while SFP28 transceivers are versatile dual-rate modules that accommodate both 10G and 25G data rates. Notably, SFP28 maintains backward compatibility with SFP+ ports and functions seamlessly at 10G. However, while SFP+ optical transceivers can be inserted into SFP28 ports, they can’t facilitate a 25G data rate.

Transceiver Structure Difference Between SFP+ and SFP28

In contrast to the structure of 10G SFP+ modules, 25G transceivers incorporate Clock Data Recovery (CDR) circuits to effectively manage the data rate leap from 10Gbit/s to 25Gbit/s.

25G SFP28 Working Principle

Maximum Transmission Distance Between SFP+ and SFP28

SFP+ allows for longer transmission distances, reaching up to 120km, whereas SFP28’s lower dispersion tolerance limits its maximum transmission distance to 40km.

Power Consumption Difference Between SFP+ and SFP28

SFP28 transceivers exhibit lower power consumption than SFP+ transceivers. This efficiency stems from SFP28’s ability to transmit the same data with less power. Consequently, SFP28 is optimal for data centers needing high bandwidth and low power usage. Moreover, reduced power consumption leads to less heat generation, diminishing cooling needs for the data center.

Cost Variation Between SFP28 and SFP+ Transceivers

SFP28 transceivers command a higher price compared to SFP+ counterparts, owing to their superior speed and lower power usage. The need for more advanced manufacturing processes contributes to their elevated cost. As data centers shift towards greater bandwidth requirements, the cost gap between SFP28 and SFP+ transceivers is anticipated to diminish gradually.

Distinct Applications of SFP28 and SFP+ Transceivers

The applications of SFP28 and SFP+ transceivers diverge significantly in terms of data transfer capabilities and compatibility. With 25G SFP28 modules, a remarkable 50G transfer data rate is achieved through only two channels. Conversely, achieving a 40G transfer data rate using 10G SFP+ modules requires four channels operating at 10G speed. This emphasizes the superiority of the 25G SFP28 transceiver when upgrading from 10-Gigabit Ethernet, offering enhanced efficiency.

Furthermore, the 25G SFP28 transceiver finds prominence as the prevailing optical module solution for 5G fronthaul applications. Its advanced capabilities and higher data transfer rate align with the demands of cutting-edge 5G networks, solidifying its role in shaping modern communication infrastructures.

Below is the comparison for SFP28 and SFP+.SFP28 vs SFP+ Transceiver

Frequently Asked Questions on SFP28 and SFP+

Q: Can I use SFP28 transceivers in SFP+ ports?
A: Yes, you can. SFP28 transceivers are backward compatible with SFP+ ports and can function properly. It’s important to ensure that the SFP28 transceiver supports a dual rate of 10G/25G, indicated as 10G/25GbE SFP28, to ensure compatibility and optimal performance.

Q: Can I use SFP+ Transceivers in SFP28 ports?
A: No, you cannot use SFP+ transceivers in SFP28 ports. SFP28 ports support data rates of 25G or 32GFC, while SFP+ transceivers typically support a maximum data rate of 10G.

However, if the switch allows for setting the port data rate to 10Gbps, you may use an SFP+ transceiver in an SFP28 port. In this scenario, the SFP28 port functions as a 10G SFP+ port.

Q: Is SFP28 better than SFP+ Transceivers?
A: Generally, yes. However, when choosing between SFP28 and SFP+ transceivers, it is important to consider your data center’s requirements, such as budget, the distance of the connections, the bandwidth requirements, and the power consumption.

Advantages of 25G SFP28 over SFP+:

  • Enhanced Performance: 25G SFP28 provides 2.5 times the bandwidth with higher port density. It also offers low power consumption and excellent thermal dispersion based on mature chip technology.
  • Broader Range of Applications: 25G SFP28 enables a 50G data transfer rate with just 2 channels, while 10G SFP+ requires four channels for 40G. It’s a superior choice for upgrading 10-Gigabit Ethernet and is a mainstream solution for 5G fronthaul.
  • Cost-effective Upgrade Path: Compared to 40G QSFP28 solutions, 25G SFP28 offers higher port density, lower power consumption, and reduced costs. The upgrade from 10G to 25G fits existing photoelectric technology and infrastructure, minimizing expenses. The industry commonly accepts the server upgrade path of 10G-25G-100G-400G.


Both SFP+ and SFP28 offer cost-effective solutions with achievable upgrade paths for high bandwidth connections. However, SFP28 stands out by streamlining infrastructures and providing a more future-proof solution with enhanced bandwidth and reach capabilities.

Bonelinks, an innovative optical transceiver supplier, offers an extensive range of SFP+, SFP28, DAC, AOC, and fiber optic cables to cater to various 25G connection applications.

Echo Huang

Echo Huang is an expert wordsmith and marketing professional at Bonelinks with more than 8 years of experience in high technology businesses – fiber optics, IoT, and telecommunication. She is very glad to share industry knowledge and communicate with others.

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