I am looking to build my first computer with the help of my girlfriends brother who has built before. I work at an architecture firm so I will be running auto CAD for 2d and google sketch up for 3d renderings. I know the CPU an going are the most important components to running a great computer. I would lik opinions on a great build that will allow me to work smoothly, stream movies from time to time and some casual gaming. I am looking to spend around $650 and I already have a monitor, mouse and keyboard. I'm do not have an intel or amd preference so please let me know what you think would work best for my situation. There is however a sale in my area for an intel i5 3470 for $150. I might be buying parts within the next couple days so please respond ASAP thank you all in advanced!!!