It doesn't matter what your score is. YOu'll be getting more frames and better picture quality on games then most people. The score of 3DMark05 is in my opinion irrelevent. The GPU will render more graphics and display a better picture quality then nearly every other GPU on the market.
But, if you want to increase that score you need new drivers. Get new drivers for you GPU. Also, download CPU-Z. This program displays EVERYTHING you need to know. Once you get that, please post a screen shot of your CPU-Z information and we'll get back to you on what is bottlenecking your system.