Info about SFP+ Cable Assemblies

SFP+ 10Gb/s assemblies are relatively new to the market and are available in both copper and fiber formats. The SFP+ interconnect assemblies support Ethernet, InfiniBand and Fibre Channel protocols. Copper based twinax cable assemblies offer short reach options for ToR or short Middle of Row (MoR) applications whereas the SFP+ fiber modules address medium to long reach applications. SFP and SFP+ standardization is specified by a MSA between competing manufacturers. Electrical and mechanical specifications for 10Gb/s SFP+ optical modules, 10Gb/s SFP + Cu (copper cables), and hosts are defined in the SFF-8431 and SFF-8083 (Electrical), SFF-8432 (Mechanical) and SFF-8472 (EEPROM) specifications developed by the SFF Committee.

10Gb/s SFP+ copper cables are increasingly popular in short reach direct attach 10Gb/s applications. Like SFF-8470/CX4 assemblies, these cable assemblies utilize twinax cable from 30AWG to 24AWG and are available in specific lengths. Therefore the same pathway considerations should be taken into account in the design. 10Gb/s SFP+ passive copper (assemblies have a reach up to 7m for Ethernet applications and longer for other protocols. The actual supported distance varies by manufacturer, conductor size and application.

Active SFP+ 10Gb/s cable assemblies utilize chips to amplify the signal and may be used to provide operation over longer or thinner cables than achievable with direct attached passive copper assemblies. The limited reach of SFP+ cables makes them suitable for use in ToR or adjacent rack switching, HPC and computing clusters for servers and storage. While these switch ports are currently lower power than 10GBASE-T copper cabling, port oversubscription must be carefully monitored to assure that per port power savings is not offset by increased electronics costs (more switches and power supplies) and their ensuing maintenance costs (which represent recurring expenses).

CX4 Cables

The overall cost of the switch port, cable assembly and server NIC should be carefully examined. Likewise, overall power, including the higher power server NIC, should be evaluated. These assemblies allow for rapid interconnection where traditional structured cabling is not available. With the advent of the SFP+ small form factor connectors, CX4 assemblies are typically used for InfiniBand copper. SFP+ connectors have become more popular in ToR switching while the market was waiting on more power efficient 10GBASE-T switches.

As these assemblies are typically confined to the same cabinet or adjacent cabinets, SFP+ Copper assemblies can help reduce pathway congestion in data centers that do not have sufficient pathway space. Major electronics manufacturers have built other capabilities into the switches to utilize both the fiber and copper SFP+ adapters, allowing either media to be accepted into the electronics slot. In most data centers, one will see a combination of the various technologies (ToR and structured cabling systems), providing the best of both worlds with technology utilization based on application specific needs. It is important to note that although the form factor is the same for direct-attached copper and fiber, interoperability from one vendor to the next may vary due to encryption methods employed by the major electronic equipment manufacturers. Varied encryption schemes may require the use of proprietary cables, which are typically far more expensive than their off the shelf counterparts.

Sopto supplies high quality twinax cables, like SFP+ cables, XFP to XFP cables, 40G QSFP+ cables, for 10G Ethernet application. For more info, please browse our website. For purchasing more fiber optic assembly products, please contact a Sopto representative by calling 86-755-36946668, or by sending an email to info@sopto.com.