XFP vs SFP+

XFP and SFP+ are the two pluggable formats for 10G optical links, and the difference between them is decided by the equipment, not by preference. An XFP slot takes an XFP module. An SFP+ slot takes an SFP+ module. The two are not interchangeable, and no adapter makes one fit the other in normal use. A buyer who knows the slot format knows the format decision; everything else is a comparison of what each format offers within its own installed base.

Size and density are the first difference. SFP+ is the smaller format, roughly the size of the earlier SFP format, and it allows denser port counts: more 10G ports per switch, per rack unit, per rack. XFP is larger, and a switch built for XFP carries fewer 10G ports in the same space. When SFP+ arrived, density was one of the reasons it took over new designs, and new 10G equipment is overwhelmingly SFP+ today. That does not make XFP obsolete for the equipment that already uses it; it makes XFP a maintenance format for an installed base that is still large.

Power is the second difference, and it runs in the same direction. SFP+ modules generally draw less power than XFP modules, because the smaller format and the newer designs behind it use power more efficiently. In a densely populated switch, the power difference across dozens of ports adds up to a real cooling budget difference. In a sparsely populated legacy switch, the difference matters less, because the total draw is smaller and the cooling was designed for the older format in the first place.

Functionally, the two formats cover the same ground. Both serve 10G Ethernet, Fibre Channel and SDH and SONET transport applications. Both come in short-reach multimode, long-reach single-mode, bidirectional and wavelength-division variants. The published XFP LR model on this site, for example, states a 10G rate, a 1310nm wavelength and a 20km reach over single-mode fiber, with applications in SDH, 10GBASE-LR and LW, and 10G Fibre Channel. The published SFP+ SR model states a 10G rate, an 850nm wavelength and a 300m reach over multimode fiber. The formats differ in shape, not in the jobs they do.

The practical advice is therefore short. If the equipment has XFP slots, buy XFP modules, and the XFP series page on this site lists the variants available. If the equipment has SFP+ slots, buy SFP+ modules, and the SFP+ series page lists the variants available. If the equipment is new, it will almost certainly take SFP+, and the density and power advantages of that format are worth having. If the equipment is legacy and still in service, keeping it running with the right format is cheaper than replacing the equipment, and the format decision is already made by the slot.

Before ordering, confirm quantity, price and delivery time during the inquiry. Certificates are available upon request.