if you expect that a 300 dolars console to do HD graphics without tearing is a bit naive of you... PC are much more expensive giving you better experiences but you get what you pay for...
BTW: not sure about this but try to put GT5 in 720p ... that should bring down the tearing (it doesn't bother me but we ain't all equals)
Proudest Platinums - BF: Bad Company, Killzone 2 , Battlefield 3 and GTA4