What does "PCI Express 2.0 Support" on the ATI Mobility Radeon 3650 mean?

I recently bought the Toshiba P300 laptop system, comes with the ATI Mobility Radeon HD 3650. The card itself is not bad, terrible performance drops when AA x4 or higher is used, hoping this PCI Express 2.0 business it talks about on the website can help me out with my performance issues. http://bit.ly/nVMVrk