Trust me dude, it's not marketing scheme, otherwise you would totally have to ignore the opinions of all of the people here who build and test different systems, as well as benchmarks.
AMD has changed their core architechture and shortened their pipelines, while Intel has kept the same long pipelines. This means that AMD can use a lower frequency to achieve high speeds, while Intel is really just left with the option to increase clock speeds.
Intel C2D E6320 / AMD Athlon X2 3800+
Gigabyte 965P DS3 / DFI nF4 Ultra-D
2GB OCZ Gold PC2-6400 / 2GB OCZ Gold PC4000
eVGA 8800GTS 320MB / eVGA 6800GS 256MB
150GB Raptor / 74GB Raptor
2x500GB / 320GB
OCZ GameXStreme 850w / OCZ StealthXStream 600w