Quixote, I would upgrade everything. The Q6600, was great, but it was great. When you buy this stuff, you want to make certain the ram will work with the MB, the chip with the MB, the PSU can support the video card etc. If you were looking to upgrade your current rig, it would have been a great idea a year and a half ago. Now, the MB is probably not adequate to support DDR3, and the 520W PSU is probably not enough to support the video card you want. IMO, it is worthwhile for you to buy the components that you know will work together. You don't want to buy half the components to find out they don't work, or worse, the new stuff is damaged when you plug it in.