IF yer goona do a lot of number crunching , using cad, cam or cas software,, you will be much happier using P4..
if you are runnign games and lots of other general softs. then either one will work,, But is is said AMD has the edge on gamming..
A majority of the big time cad, cam and cas softs are optimized using the intel platform. Now, how do I know this,,, Well, this is not just an opinion based upon feelings speculation and rumor. It is a fact that some CADs will run its best on P4's
Our computer local computer shop (for whom i used to be a silent partner and tech) builds numerous machines for our local the NASA test sites, Lockheed Martin that builds the shuttle fuel tanks, and textron that builds the LCAC navy crafts. They specify P4 machiines for a good reason. Experience shows that P4's run faster and crash rarely running CAD, and CAM softs
While AMD crashes more. This is not an issue when running word or DOOM III.
But it is when rendering graphics that take minutes to redraw. A crashing machine takes out huge bites of research time. We all know how long it takes to boot XP and then load software. Then unpack and load up a 80 meg tiff or DWG file. Three crashes a day is just too much. So, with P4's they have very few crashes.. 3 seconds slower on a redraw is not much when you redraw just one every 10 minutes. But when you redraw hundreds of times a day, ,You will soon see the diffrence.
For general computing there is not much difference. AMD platform's claim to fame is the ability to overclock. This is a plus to money strapped hobbyists because with a little weak and they are running faster with older hardware.. P4's are locked and cannot be tweaked as much. That is why so tweakers / hobbiests advise you to get a AMD.. They can get more use for the same buck. But, when it comes to production then who cares about squeezing out a few more months of usage.
Engineering houses want speed NOW!. They also do not care bout making a machine last. They upgrade as fast as their budget allows..
Personally, I use P4's at the office and AMDs for the kids gaming machines.
Have fun.