I made my first pc last month. I after reading and looking at all the cpu choices I went for a AMD 64. Why would I do that? For one it runs cooler and another it benchmarks more than a pentium 4 3.2ghz even though my 3200 only runs at 2.2ghz.
I was told they were good. So I went with one. It is amazing how fast this thing is! It runs cool and is very fast.
The thing is all your programs now run in 32bit. They will be twice as fast and way better when they get into 64bit.
Though 64-bit computing has been around for some 14 years or so, until recently it has been accessible only to those operating high-end servers running RISC-based processors such as Sun Microsystem Inc.'s SPARC, IBM's Power and Hewlett-Packard Co.'s PA-RISC.
See they have been around for a while but only big systems for work have them. Now as more and more programs are power hungry for not just big work computers but your home computer 64bit is coming.
I have a link for you that might help.http://www.eweek.com/article2/0,1759,1776011,00.asp
I hope this helps. If you have any more questions just ask.
My advice dont go for anything else.