I would first buy a graphics card. The one you have on your motherboard will not take advantage of any overclock you give it. If your will to spend money I could suggest graphics cards that I believe to be the best at your budget. If your search on ebay for one at a 50 dollar price range, it will be light years ahead performance over your current one. I would say this is better than any 500 dollar computer upgrade since visuals mostly rely on graphics cards, alsomost prebuilt computer come with horable cards.