The GD65 offers more phases in its power design, bigger heatsink, plus voltage checker and OC buttons on board, which is great for heavy overclockers ( 5.0ghz and beyond ), plus the GD65 gaming has 3 full-speed PCI-E X16 slots, while the G45 gaming only has 2. Last big different would be more sata3 ports in Gd65. Other than that, not many significant differences between the 2 boards.