Your card should play that game ok, I'd think the CPU upgrade would help feed data to your video card much more effectively. To me, it'd be worth $40 on ebay to see, after all the E8600 is 1000mgz faster... I'm not seeing any reason you couldn't swap it in and have a much faster system. No way to guarantee how an older system responds without just trying it out. I'd go for it, if it was me.