GBIC vs SFP vs SFP+ vs XFP, what’s the distinction?

GBIC, SFP, SFP+, and XFP are all terms for a type of transceiver optics that plugs into a special port on a switch, router or other network devices to convert the port to a copper or fiber interface. The commonly used SFP, SFP+, and XFP are all with LC connector. SFP and SFP+ with an identical pinout that is different with XFP transceivers. Both SFP+ and XFP with DDM function as a default, whereas SFP partly supports DDM function.

Comparison: SFP vs GBIC vs SFP+ vs XFP

 Optics Type Standard Data Rate Wavelength Fiber Type Max Distance Typical Connector DOM Operating Temperature
 SFP SFP MSA 155Mbps
622Mbps
1.25Gbps
2.125Gbps
2.5Gbps
3Gbps
4.25Gbps
850nm
1310nm
1550nm
CWDM
DWDM
BIDI
OM1
OM2
OS1
OS2
160km LC   SC    RJ-45 No or Yes Commercial
Industrial
 GBIC GBIC MSA 155Mbps
622Mbps
1.25Gbps
850nm
1310nm
1550nm
CWDM
DWDM
BIDI
OM1
OM2
OS1
OS2
120km SC   RJ-45 No Commercial
Industrial
 SFP+ IEE802.3ae
SFF-8431
SFF-8432
6Gbps
8.5Gbps
10Gbps
 850nm
1310nm
1550nm
CWDM
DWDM
BIDI
Tunable
Copper
OM3
OM4
OS1
OS2
120km LC Yes Commercial
Industrial
 XFP IEE802.3ae
XFP MSA
6Gbps
8.5Gbps
10Gbps
850nm
1310nm
1550nm
CWDM
DWDM
BIDI
Tunable
Copper
OM3
OM4
OS1
OS2
120km LC Yes Commercial
Industrial

Figure 1   A Typical SFP SFP+ XFP Optics

1.25G Multi-mode 850nm 550m SFP SX Optical Transceiver      10Gb/s MMF 850nm 300m SFP+ SR Optical Transceiver Module       10Gb/s MMF 850nm 300m XFP SR Optical Transceiver
SFP VS SFP+ (SFP Plus)

SFP and SFP+ with a similar form factor dimension hence look like the same.
SFP optics usually support 155Mb/s,1.25Gb/s to 4.25Gb/s while SFP+ ones supports data rates up to 8.5Gb/s and 10Gb/s.
SFP is for Fast Ethernet, Gigabit Ethernet,1x/2x/4x Fiber Channel, and SDH/SONET with data rate below 2.488Gb/s applications. SFP+ for 10 Gigabit Ethernet,10G SDH/SONET applications. SFP is compliant with IEEE802.3, INF-8074, and SFF-8472 while SFP+ is compliant with the protocol of IEEE 802.3ae, SFF-8431, SFF-8432.

XFP VS SFP+ (SFP Plus)

XFP is a separate standard that also supports 10Gb/s speeds for applications of 10 Gigabit Ethernet, 10 Gbit /s Fibre Channel, Synchronous optical networking (SONET) at OC-192 rates, Synchronous optical networking STM-64, 10 Gbit /s Optical Transport Network (OTN) OTU-2, and parallel optics links.4. The primary difference between SFP+ and the slightly older XFP standard is that SFP+ without the chip for clock and data recovery that makes an SFP+ smaller than an XFP, enabling greater port density. However, some SFP+ optics manufacturer like Optcore has developed SFP+ with CDR that for special applications. XFP is defined by XFP Multi-Source Agreement that is different with SFP+ MSA. Since SFP+ smaller dimension than XFP that provide a higher port density in switch and routers, nowadays it becomes more and more popular.