This didn't seem to post before, so I'll try again.
How does the Intel Core i3 compare to the Pentium 3 or Pentium 4 with regard to software requirements for the processor? If my software requires a Pentium 4, will the Intel Core i3 be fine?
Its not even comparable, the lowest level i3 is many times faster than even the fastest pentium 4. If the software requires a Pentium 4 and you have an i3 it will run perfectly fine.