Built on the previous 256MB 7800 GTX, the XFX XXX Edition GeForce 7800 GTX Video Card by NVIDIA is the fastest PCIe video card available. The main differences are the increase to 512MB of DDR3, as well as increasing clocks speeds and improving cooling systems.
The memory clock speed was increased to 1.7GHz (from 1.2GHz) as well as the core clock speed being increased to 550MHz (from 430MHz). Additionally, this graphics card comes overclocked straight from the factory, adding a 30MHz increase to both figures.