I have an existing Compaq box: SR5710F, which has a processor: Athlon X2 (B) 4450e 2.3 GHz (45W) I just noticed that this box is not fast enough to compute some of the more sophisticated indicators I developed. I need a faster CPU. When shopping for some of the newer desktops, such as HP e9220y Desktop PC, it has a processor: Phenom II X4-910 (D) 2.6 GHz (95W) The processor speed looks good. But when I read the specs, I found that this box only has 2 PCIe x1 expansion slots available. It would mean I have to completely change out my video cards (currently PCI base). Not only that, I only would have 2 of them. I can only drive 4 external monitors. (Currently I use 6). Not preferrable. My PC hardware knowledge is very limited. Can anybody tell if I can just buy a faster processor chip, such as the "Phenom II X4-910 (D) 2.6 GHz (95W)" that I like, and replace the current one "Athlon X2 (B) 4450e 2.3 GHz (45W)" with it? Or different CPU chips have different pin layout pattern, power requirement and clock speed requirement etc that I must change out the motherboard as well? Or any suggestion on buying a faster box that has 3 PCI slots and it doesn't cost an arm and a leg?