This message was posted on behalf of Intel Corporation
I understand you are having some question of how the PCIe lanes are distributed. Allow me to help you regarding these questions you are having.
In this case, the lanes that the processor provides are, as you mentioned, just for graphics. The motherboard will provide extra PCIe lanes nonetheless; the purpose of those lanes will be different, for example, a Wi-Fi card or Raid controller. There is no way to split the lanes, the motherboard will make sure are correctly distributed. In the case you would like to do a deeper research about the distribution you can look for support on our Developer Zone or in Resource and Design for Development with Intel®.
I hope this answers all your questions.