Should be fairly obvious, it would be a bottleneck. The Ram is good, that is enough for gaming, however if you really want to get better frames my first recommendation would be to upgrade your CPU. If you're on a budget, go for an i3, however if you are not, you should probably go for an i5. I will recommend the 3570k, however if you don't have an overclockable motherboard, you should go for an i5 3550, or a motherboard that supports 1155, then you should go for a Asrock Z77 Extreme 4 coupled with a 3570k.
The 670 is a great card, but its definitely going to be held back by that processor.