To sum it up I would say that it is because of your graphics card. The FX5600 is basically like the Geforce4 MX range of cards for the FX series, so basically your not expecting much out of them. If its something like the FX5900 or higher up or ATI Radeon 9700 & up then you would expect a huge score increase. Anyways if your games run perfectly fine, then it still shows that your graphics card is up to it. Don't let benchmarks tell you otherwise.