So I'm looking to build my first gaming pc. I've been operating under a budget of about 700 dollars (I still need an OS, so only 600 for parts) but I suddenly came into some extra money and now I have an additional 100 bucks to spend. I can't decide if I should put it into the cpu or the video card.....I do want to do a reasonable amount of multitasking. The extent will likely be fraps, a game, and some browser tabs. With this in mind, should I upgrade from an i3 to an i5? Or, alternatively, should I upgrade from a 6870 to something like a 7850?