So I'm anxiously waiting on my tax refund. I am gonna build myself a new gaming rig. However, I've got some questions. I plan to stick with AMD and I'm going with a 64 bit processor. I am looking at the Athlon 64, 64 X-2, and 64 FX series chips. I am planning on going as high as possible. I'm primarily looking at the 64 and 64 x-2's, as the FX are a little to pricey. Is dual core gonna be a significant improvement? Is the FX worth the huge price jump from the X-2? I will be running XP-64 for now, I plan on waiting for Vista to be around before upgrading. Our should I skip that and just put 2 SLI gfx cards in? Also, what is the technical difference between 90 nm and 130 nm processor? Anyone have a recommendation on system boards? I've had real good luck with the nForce boards, and figured I would go with one again.