Would going from ddr2 ram 400 to 667 make a noticeable difference in speed of computer?

Between the two different types of RAM, the difference in benchmarks is about 2-3%, in the real world it is not noticeable. Your comparison between the two system is harder. First they both do not have 1333mhz FSB.

In fact core i5 series processors do not have a front side bus at all. The MCH or more commonly called the "northbridge" is now on the CPU die itself. The Core i5 in my opinion would win your second comparison.

Well as far as I know if you were comapring the core i5 and core2 systems the amount of memory bandwidth between the two would be significantly higher on the core i5 as it has a on chip memory controler, also having the higher frequency ram would be notably faster on both systems with the i5 showing best results.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.