Cache memory is the RAM onboard the CPU (in essence). You will notice a big
difference in the 1MB of cache.
If you can buy an athlon x2 6400+. They are about 180 now. 3.2GHzx2 is
nuts.
Also try the q6600 for about 225. Very good processors. The E4500 is not
very good, the 4400+ is probably a bit better.