Hi there. Trying to upgrade my Dell dimension 2400 without changing motherboards, etc. It's running on a Celeron d 2.4 Ghz., Socket 478, Intel Chipset 845. I am happy with the video, which goes at least as high as 1600x900. I also added RAM, and am running on 2 GB. Now, concerning the CPU, there are higher Celeron D, like 3.06 and even 3.20 with that socket #. Would I really gain anything processing speed by using one of these? Thanks for getting back to me.