The line rate support radio buttons allow the selection of individual line rates. The radio buttons default to fully support the line rate selected in the configuration tab. If the design is to run at only a sub-set of these rates then unused speeds can be turned off by deselecting the relevant radio buttons.
For example, to generate a core with a maximum line rate of 4915.2 Mb/s, select the 6.144G and under option in the Configuration pane. The 6144.0 Mb/s support radio button in the Optional Features pane can then be deselected to change the maximum supported line rate. Deselecting unused line rates can result in improved logic optimization during the implementation phase.