Looking to upgrade my PC.?

I currently have a Quad Core computer with a high-end graphics card and sound card. I am looking to upgrade my Quad Core to something along the lines of a Hex Core Processor. My question is, to do this would I have to purchase a new Motherboard to fit such a Processor in it? If not, any suggestions on gear that would be helpful to upgrade that would help better my PCs ability to run upcoming games and such. Thank you for your help.