WOW that was a fast answer.
Thank guys
Another thing is. If I have a person that would buy from me my MB, CPU, and memory, for lets say 500$ do you think I could find a conroe setup for a decent price without putting much more money?
Sorry for my english.
Dude, thats not worth it at all. You can get either one of those X2's I was talking about for around $250-$280 off newegg.com. Thats much better and less expensive than starting over with new Ram, Motherboard and CPU.
The only benefit that Conroe will give you in gaming is if you game at 1024X768 or less resolution. Crank up the Res to 1280X1024 and other graphical settings and the X2 will do just as good.
Here's an example of a statement that is true varying on too many other variables to be deemed factual.
You see, when gaming at 1280x1024 or higher the Athlon64 X2 processor won't do as good as you say. It is still slower by 20-40% but your system is limited by the video card (in the case of single GPU/VPU configurations that is). Therefore the Core 2 Duo system is being slowed by this bottleneck, held back from achieving it's true potential.
Now for the variables I was talking about... replace that 7900GTX/x1900XTX with an nVIDIA G80 (coming mid-November) or an R600 (coming mid-January) and your results are quite different. No longer is the system AS bottlenecked by the video card.
So, given the past performance increase in Video Cards it's safe to say that current titles bottlenecked to 1280x1024 will play with full fluidity up to 1600x1200 or higher on a single graphics card.
Therefore that Core 2 Duo that is 20-40% faster per clock then that Athlon64 X2 will be offering 20-40% more performance as it is no longer being held back by the Video card.
So, to tell someone to omit considering a Core 2 Duo under these circumstances is not advised.
FACT is.. Core 2 Duo's are 20-40% (sometimes even more up to 60% on some tests) faster per clock then Athlon64 X2 processors and the cost is around the same.
If you wait until 3rd quarter 08 when the new Light-speed-super-dupper-video-mega-chipbuster-R1000 version b comes out, you will see a %150 increase in blah, blah, blah.......
The OP wanted to know if he can upgrade to a Conroe system for about $500-$600 that will give him worthwhile improvement playing games over what he has now.
Answer to his question following the parameters HE HAS SET, no.
That G80 or R600 will probably cost close to that much by itself, no ones knows for sure as they are not even available yet.