please help how can I determine which is the best to use for a computer I am going to build am new to building comp am tired of porpriatary machines with no upgradeability
Buy a AMD, don´t even consider a P3!
You have to pay more for a P3 than a AMD (In sweden anyway) so I really don´t see why you would want one.
Upgradeability? AMD is by far a better choice than a P3!