SFP+ vs XFP: What's the difference?

SFP+ and XFP are both types of optical transceivers used in high-speed data communication networks, but they have some key differences in terms of form factor, applications, and design. Here's a comparison of the two:
1.Form Factor:
· SFP+: SFP+ (Small Form-factor Pluggable Plus) is more compact than XFP and is the successor to the SFP module, designed to support 10 Gigabit Ethernet, 8 Gbit/s Fibre Channel, and other protocols.
· XFP: XFP (10 Gigabit Small Form-factor Pluggable) is larger than the SFP+ and was one of the earliest transceiver designs for 10 Gigabit Ethernet.
2.Data Rate:
· SFP+: Typically designed for 10Gbps, but variants can operate at lower speeds, such as 1Gbps.
· XFP: Primarily designed for 10Gbps operations, but it can support other data rates close to 10 Gbps.
3.Applications:
· SFP+: Became the standard choice for 10G Ethernet and has mostly replaced XFP in newer installations because of its compact size.
· XFP: Was significant in the early days of 10G Ethernet roll-outs but has been largely replaced by SFP+ in more recent applications.
4.Electrical Interface:
· SFP+: Uses a direct-attach approach without a defined electrical interface between its module and the host.
· XFP: Uses the XFI (10 Gigabit Attachment Unit Interface) electrical interface.
5.Protocol and Link Length Independence:
· SFP+: Depends on the specific model and application.
· XFP: One of the design features was protocol and link length independence, allowing for flexibility in choosing the protocol and fiber type (e.g., single-mode or multi-mode).
6.Power Consumption:
· SFP+: Typically has lower power consumption compared to XFP because of its more compact and efficient design.
· XFP: Generally consumes more power than SFP+.
7.Hot-pluggability:
· Both SFP+ and XFP modules are hot-pluggable, allowing them to be inserted or removed without shutting down the host equipment.
In summary, while both SFP+ and XFP were designed for 10 Gbps operations, the smaller, more efficient SFP+ has become the preferred choice for most 10G Ethernet applications, especially in data centers where density and power consumption are significant considerations.
 

XFP vs SFP+: Specifications

XFP vs SFP+, what are the differences? Although both of these modules are mainly used in 10G fiber optic networking, 10G XFP transceivers differs from 10G SFP+ optics in some specifications. Let's look at the details from the following figures.

Optical Type	XFP	SFP+
Standard	IEE802.3ae; XFP MSA	IEE802.3ae; SFF-8431; SFF-8432
Publish Time	2002	2006
Size	Bigger	Smaller
Data Rate	6Gbps; 8.5Gbps; 10Gbps	6Gbps; 8.5Gbps; 10Gbps
Wavelength	850nm; 1310nm; 1550nm; CWDM; DWDM; BIDI; Tunable; Copper	850nm; 1310nm; 1550nm; CWDM; DWDM; BIDI; Tunable; Copper
Fiber Type	OM3; OM4; OS1; OS2	OM3; OM4; OS1; OS2
Typical Connector	LC	LC
Max Distance	120km	120km
Cost	Higher	Lower

 
Through comparing XFP vs SFP+, it is clear that SFP+ shares some advantages over XFP:
10G SFP+ optics has a smaller footprint than the XFP modules, which can also enable greater port density. That is because SFP+ transceivers leave more circuitry to be implemented on the motherboard instead of its inside — it moves some functions to the motherboard, including signal modulation function, MAC, CDR and EDC. Moreover, XFP technology is relatively older but more expensive, that's also the reason 10G SFP+ modules have been gaining more market share.
 
 

What do SFP+and XFP mean respectively?

 

What is SFP+？

 
SFP+ is an upgraded version of SFP, which is defined by the SFP+ Multi-Source Agreement (MSA). It was officially released on May 9, 2006, and version 4.1 was released on July 6, 2009. The SFP+ optical module is a small, hot-swappable 10G optical module that complies with IEEE 802.3ae, SFF-8431 and SFF-8432 protocols, and can work at 850nm/1310nm/1550nm wavelengths, and is used in 10G Ethernet and 10G fiber channels. , 10G SONET/SDH, OTN, CPRI wireless, 16G Fibre Channel and 32G Fibre Channel.
 
SFP+ (Small Form-factor Pluggable Plus) is a compact, hot-pluggable transceiver module used for both telecommunication and data communication applications. Here are some key points about SFP+:
1.Data Rate: SFP+ is an enhancement of the SFP design and supports data rates up to 10 Gbps, making it suitable for 10 Gigabit Ethernet, 8 Gbit/s Fibre Channel, and other higher-speed applications.
2.Form Factor: The physical size of SFP+ is the same as the regular SFP, allowing for backward compatibility in terms of port size. However, not all devices support the insertion of an SFP+ into an SFP port, especially if they're not designed to handle the higher data rates.
3.Types of Connections: SFP+ can connect with both optical (fiber) and copper cables, though the optical versions are more common. The kind of medium it can interface with often determines its range, with some modules suitable for very short connections (like within the same rack) and others capable of transmitting data over several kilometers.
4.Applications: Beyond just 10 Gigabit Ethernet, SFP+ modules are utilized in other high-speed protocols such as SONET and SDH.
5.Low Power Consumption: Relative to other 10 Gbps transceivers, like the XFP, SFP+ has a lower power consumption, making it an attractive choice for data centers and enterprises looking to manage energy costs.
6.Direct Attach Copper (DAC): SFP+ is also available in a Direct Attach Copper configuration, which uses a passive twinax cable assembly to connect directly between SFP+ ports without the need for transceivers at all. This is especially useful for short connections, such as within a rack or between adjacent racks.
In essence, SFP+ offers a compact and efficient solution for achieving higher data rates in modern networking equipment while maintaining the small form factor that is valuable for high-density port configurations.
 

What is XFP？

XFP is defined by the XFP Multi-Source Agreement (MSA). It was announced on July 19, 2002, officially launched on March 3, 2003, and later updated in a small range on August 31, 2005. XFP optical module is a 10G optical module that is hot-swappable and independent of the communication protocol. It can transmit data at 850nm/1310nm/1550nm wavelength. It is mainly used in 10G Ethernet, 10Gbit/s fiber channel, OC-192 Digital transmission, synchronous optical network STM-64, 10Gbit/s optical transmission network (OTN) OUT-2 and parallel optical fiber link.
 
XFP (10 Gigabit Small Form-factor Pluggable) is a standard for transceivers for high-speed computer network and telecommunication links that use optical fiber. Here are the main characteristics and features of XFP:
1.Data Rate: XFP is designed to support a range of optical transport standards, including 10 Gigabit Ethernet, 10 Gbit/s Fibre Channel, and other protocols, all operating at data rates around 10 Gbps.
2.Form Factor: The XFP module is larger than the more recent SFP+ module, which also supports 10 Gbps operations but in a more compact form factor.
3.Hot-pluggable: Like the SFP and SFP+ modules, XFP modules are hot-pluggable, which means they can be inserted or removed without shutting down the host equipment.
4.Interface: XFP modules utilize a standardized electrical interface, known as XFI, which provides a separation between the optical components and other circuitry, allowing for flexibility in design.
5.Applications: XFP modules were among the first transceivers to support 10 Gigabit Ethernet, making them critical during the initial roll-out of 10G networks. They've since been largely supplanted by the smaller SFP+ in many applications but are still found in some legacy installations.
6.Independence: The XFP design was developed with the idea of providing protocol and link length independence. This means that the choice of protocol and the choice of fiber type (single-mode, multi-mode) or link length can be made independently in the XFP module.
7.Power Consumption: XFP typically consumes more power than SFP+ due to its larger size and older design. This can be a consideration in high-density data center applications where power and heat dissipation can be concerns.
While XFP was significant in the initial deployment of 10 Gbps networks, the evolution of transceiver technology, particularly with the introduction and widespread adoption of the smaller SFP+ modules, has led to a decline in the use of XFP in newer installations.
 

XFP vs SFP+ Compatibility

For module-to-module compatibility, It is feasible to interconnect XFP and SFP+ modules with a matched fiber patch cable. The connectors of XFP and SFP+ fiber transceivers are both LC duplex. Therefore XFP and SFP+ modules with the same protocols, wavelength, and other specifications can interoperate via a duplex LC fiber patch cable.
For module-to-port compatibility, XFP ports cannot take SFP+ transceivers and vice versa. Given that the width of XFP is much wider, the electrical interface of XFP (XFI) is inconsistent with the electrical interface of the SFP+ port (SFI). XFP modules that are inserted into XFP ports are not replaceable for SFP+ modules.