You can replace the cpu last, however. You can OC that chip to 3.3GHz without changing its voltage...3.7 @ 1.55v. DO NOT exceed that voltage. For a little more stability I'd bump the voltage to 1.4 even for a mild OC. Monitor/upgrade cooling.
Windows 7 64 (not a fan of W8), new mobo and more ram will increase your performance tremendously. Some great gpus available for modest prices, right now.
You should see the Crossfire Technology logo in the corner of your game (if supported) screen when it is functioning. Enable this by right clicking "small" AMD logo in your toolbar, hover over the gpu description and left click the "AMD CrossfireX Settings".
12:55 AM by