Athlon Dual Core and Ubuntu... problems or warnings?

[Dave M G]

Ubuntu Users,

I am purchasing a new computer that will be an Ubuntu Linux box. The 
store that I am purchasing from has a decent price on Athlon 64 dual 
core CPUs. It's still a little more than the Pentium 4 which is my 
original choice of CPU.

 From my understanding, 64 bit may not be all that useful, as all my 
applications probably don't take any advantage of it.

But dual core should provide a noticable boost in performance, shouldn't it?

Are there any recommendations for or against purchasing an Athlon 64 
dual core CPU for Ubuntu?

Any advice would be much appreciated.

Thank you.

--
Dave M G