You lose fanboy.
Heres a line taken out of AnandTech review of C2D vs AMD
In fact, in a complete turn around from what we've seen in the past, the highest end Core 2 processor is actually the most efficient (performance per Watt) processor in the lineup for WME9. This time, those who take the plunge on a high priced processor will not be stuck with brute force and a huge electric bill.
Heres a page in the article about how the FSB is lower
Clearly shows that the performance increase is minimal.
Now heres there part where I blow up your little Fanboy thoughts of at the lower-end AMD being more cost efficient.
Now lets take a look at Inteles E6300 vs the 4200 x2
They both range about $180
Take a look at the Overall General SYSmark
At stock speeds the E6300 beats the 4200 x2 in every category on that page. A few things are just by a few points while others the E6300 beats the FX-62. Clearly on that page The C2D E6300 would be a better choice for your $180 bucks.
Then you can take a look at wordbench where E6300 beats it only by one point. So even though Intel wins ill say well 1 point isnt much you can get a 4200 x2 if thats what you were going to use it for no big deal there.
Then the next page in that article shows general Performance Winstones.
In the top one E6300 gets beat by a few points, while in the next one its get beat by about 3 points. So if thats what you are going to use your computer for (Winstone 2004) by all means get an AMD, I mean i know thats what i want to be really fast, My Winstone 2004. LMAO
Next 2 pages you'll see the next few AMD seems to win by a few points every few times. So if thats exactly what your PC will be used for the most, Encoding and Rendering then buy the 4200 x2.
But now heres the big one. If your going to use your Computer for Gaming (as most on this site in the high-end section do) check the marks there.
You will see that in the majority of games Intel wins. Their E6300 is either about 2 points behind, or faster than the 5000 x2.
So you could say the E6300 slighly beats the 4200 x2 on average then. But since your a huge Fanboy and I doubt the becnhmarks are going to your head i'd say that your 4200 x2 is fine even though its a bit weaker.
Now heres the killer though try to OC a 4200 x2 a bit and man you can reach what 4600 speeds?
Now OC the E6300 and you can reach speeds of 3.6ghz
Thats about a 100% increase in frequency while the AMD can get what about 25% at most?
Even a slight OC to about 2.4 in tests have already priven that thae E6300 at 2.4 will beat the FX-62 in most tests.
Just take your fanby self away and look at the factsa. For now Intel is King