Well, then a CPU upgrade will make a big difference. And since you're going from socket 745 to s939, you have the benefit of dual channel memory as well. Not sure if you'll see a massive increase in framerates, since the 4600 has a slower stock speed than you current CPU, and most games aren't optimised to support dual cores, but I reckon you should see a little increase. Not sure if it's worth the money, but it would be better in the long run to go dual core. Hope it helps. As for the bottlenecking, don't let Gaara see this post, or you'll see a rant about bottlenecking, and what it refers to!