As you know by now I am getting a AMD 64 3400+ well I was wonderng if the AMD 64 3400+ is really powerful enough to help my 9600XT acheive 100FPS in some games.
I am upgrading the 9600XT to a 6800Gt but probaly not for another few months.
I think it's more a case of your 9600XT being the bottleneck, rather than the CPU. Whether or not you can achieve 100fps depends on the game. In games that use the Quake 2 and 3 engines, this would be easily achievable. In a newer game, such as Unreal Tournament 2004, you'd struggle to get close without sacrificing graphics detail.
You will certainly see improvement, and perhaps a rather dramatic one. All we're pointing out is that, as far as 'high performance' display cards go the 9600XT probably just scrapes in at the bottom end!