|There were two different groups that wanted two different standards: members who were interested in faster server-to-switch applications wanted 40Gbps, whereas other members who were more interested in developing a more robust network backbone favored the higher 100Gbps speed. The higher speed would require more expensive and power-hungry equipment...|
In the end, unable to come up with a consensus, the HSSG decided to standardize both the 40Gbps and 100Gbps speeds as part of the IEEE 802.3ba spec, with connection equipment for speed having different physical specifications. 40Gbps links can be up to one meter long for switch backplanes, 10 meters for copper cable and 100 meters for fiber optics. The 100Gbps spec will add specifications for 10- and 40-kilometer links over single-mode fiber.