actually .. here's the deal .. the AMD Semrpon is a lower end processor, like Intel's Sempron (AMD Athrlon is to Pentium 4 what Semrpon is to Celeron) .. the Pentium 4 is a decent, but out dated, processor .. you're probably going to be hard pressed to find a replacement processor that fits your motherboard .. all processors since the P4 were scaled down .. the Pentium 4 Extreme Ed. I have in my old Gen4 XPS is 90nm while newer Core 2 Duo's/Quads are 45nm (with one Core 2 Quad I found at 65nm) .. so odds are your P4 is 90nm or bigger, and they just don't make 'em that big anymore .. if you wanted an AMD processor, you'd have to replace your motherboard as well because AMD processors won't fit into Intel motherboards .. kinda like the square peg in the circle hole analogy .. either way .. whether you upgrade to intel or AMD you're going to have to replace your motherboard .. It's honestly a toss up between the 2 .. AMD's are great and so are Intel's .. AMD's core architecture seemed to streamline data a little better than Intel's .. honestly, the differences break down to technical specs and the architecture of the chip themselves .. they are both good CPUs .. AMD actually boasts that there processors, rated at lower clock speeds, actually perform as well as higher rated Intel CPU's .. so the choice is yours .. ;]hope this helped!!