It will be more than twice as fast overall I believe. If you overclock it to 4GHz, even more. The graphics chip inside the i3 CPU is not even in the same league as the 8600m gs. It's not even as good as a radeon 3200 integrated. But since you are not gaming and have not mentioned anything else you might do that is graphics heavy, it doesn't matter. It will be good enough to play HD movies, maybe play the occasional call of duty 2 at minimum settings.