Really though if you build a high-endish computer. i7-2600k or AMD 8-core, you are good for 5-6 years, with an upgrade of the graphics card after 3 years. My current desktop is 2 years and I'm gonna upgrade the 4870 and go SSD and thats about it. I have a phenom ii x4 black and 790gx chipset. Its still a good setup, hell we've only just started coming out with software to utilize the 4 cores.

Just my opinion