I know these are kind of older cores but I have no knowledge on processors. I originally had the core 2 I'm my system, but then I bought my parents a computer and it came with a Pentium d. I saw that it both was duel core and I saw the Pentium d had higher GHz and switched them out. But from what I here in these forums the core 2 is better. Which one is better and should I switch them both out again?