elayman

So I have an intel Pentium D 2.8ghz processor that i swapped from my asus motherboard into my gigabyte motherboard that supports core 2 duo and core 2 quad core processors and it runs fine. I then attempted to buy a core 2 duo for my asus and it won't boot.. the monitor won't even show a signal. Anyways I stuck the D back into the asus and it runs fine. Now my question is, what is the difference? Is a 2.5ghz core 2 better than a 2.8 D processor or are they about equal? I've spent so much time and money on these two computers in the past 4 days it's unbelievable. At least 6-8 trips to frys because parts weren't compatible, which was my fault, although I don't have the manual for either motherboard which makes it hard to know.. I even brought the motherboard and the people told me it would fit.... Someone educate me on processors