Howcome the xbox 360 has lower specs than my PC but the games of the xbox run smoother?

Games run fine on my PC on ultra max settings in every game iv showcased on my youtube channel granted its not much lol but my pc blows 360 into tiny little peices. Most modern pc's with a decent card will blow away current gen consoles.

-mrGREEK360
My Youtube channel having weird fraps artifacts in my vids. http://www.youtube.com/user/liquidg

Alienware X51
Intel i7 3770
16GB DDR3 1600MHz
Nvidia GTX 660 OEM 1.5GB DDR5 RAM Overclocked
1TB 10000RPM
BLURAY Burner
Sharp Quattron 60" 1080p 240Hz 3D HDTV - I cant play on small monitors even tho i'm stuck with 1080p but it works out great for recording game footage. :) I also use 360 controller as im on a couch... Multiplayer I use mouse keyboard

GTA IV is an infamously bad console port, no wonder it is optimized like a turd

I stopped reading at "GTA4". It is a really really bad port, that's the only reason.