Aspects relate to link speed for a peripheral component interconnect. In one aspect, an apparatus includes an interface circuit configured to provide an interface with a multiple lane data link, the data link having a first set of lanes in an active state and a second set of lanes in an idle state and a controller. The controller is configured to receive a request at the controller to change a data rate of the data link to a requested data rate, change the second set of lanes from an idle state to an active state, train the second set of lanes to the requested data rate, transfer data traffic from the first set of lanes to the second set of lanes after the training, and transmit the data traffic on the second set of lanes.