How much better is this P4 processor than my old one?

thats like compareing apples and bad apples sure p 4 is better than celeron the latter was made to compete against like p3 and stuff but somethng like the athlons are a better match and they both clock about the same search your chipset and get the biggest fastest chip that will fit if you cant find anything but p4 go for it its all single core anyway and maybe with luck you may find a hyperthreader but i think not buy a new one and not off of ebay and check tiger direct they have great deals