Gazettabyte

The next-generation CFP modules - the CFP2 and CFP4 - promise to double and double again the number of 100 Gigabit-per-second (Gbps) optical module interfaces on a blade.

Using the CFP4, up to 16, 100Gbps modules will fit on a blade, a total line rate of 1.6 Terabits-per-second (Tbps). With a goal of a 60W total module power budget per blade, that equates to 27Gbps/W. In comparison, the power-efficient SFP+ achieves 10Gbps/W.

Source: Gazettabyte, Xilinx

The CFP2 is about half the size of the CFP while the CFP4 is half the size of the CFP2. The CFP4 is slightly wider and longer than the QSFP.

The two CFP modules will use a 4x25Gbps electrical interface, doing away with the need for a 10x10Gbps to 4x25Gbps gearbox IC used for current CFP 100GBASE-LR4 and -ER4 interfaces. The CFP2 and CFP4 are also defined for 40 Gigabit Ethernet use.

The CFP's maximum power rating is 32W, the CFP2 12W and the CFP4 5W. But vendors that put eight CFP2 or 16 CFP4s on a blade still want to meet the 60W total power budget.

Getting close: Four CFP modules deliver slightly less bandwidth than 48 SFP+ modules: 4x100Gbps versus 480Gbps. The four also consume more power - 60w versus 48W. Moving to the CFP2 module will double the blade's bandwidth without consuming more power while the CFP4 will do the same again. a blade with 16 CFP4 modules promises 1.6Tbps while requiring 60W. Source: Xilinx

The first CFP2 modules are expected this year - there could be vendor announcements as early as the upcoming OFC/NFOEC 2012 show to be held in LA in the first week in March. The first CFP4 products are expected in 2013.

Further reading

The CFP MSA presentation: CFP MSA 100G roadmap and applications