We are having our pc's upgraded at work. The current ones are about 3 years old. They have a 3.06GHz pentium 4 cpu running at 133Mhz x23 according to the bios. The replacement pcs are Hewlett Packard xw6400 Xeon 5140 machines and according to the blurb run at 2.3Ghz. I'm not at all up to speed with Intel chips these days so can someone assure me that this new pc will be faster than the old one in raw number crunching terms, when running single core apps? How much faster would it be ball park if it is faster.