Please list your entire build with the specifics about each part. Intel has made dozens of dual core CPUs over the past decade.
An early thought, you won't be able to play BF4 on high settings because of your computer. If your computer uses DDR2, it will most likely have an Intel E series dual core. BF4 requires a modern quad core to play. Buying a new GPU won't fix your issue. You will need to build/buy a new computer to play games at the level you want.