If u r gaming only at 1080p monitor. Then u dnt need the 4gb model. Its jst the waste of money.
But if u r gonna do video editing then u would definately benifit from 4gb vram. U would benifite in gaming only when u play games at higher rez like 1440p or greater.
There is no diff in those two cards except for 2gb extra vram in 4gb model and slightly diff clock frequency.
I would suggest u to get an "sapphire TOXIC r9 270x". Its the fastest 270x gpu out there. But its also a long gpu. It measures 12.13inch or 308mm. So b4 decide to buy make sure ur cabinet supports that long graphics cards.
Or u can jst wait another month for the r9 300 series graphics cards. Which wil b much more powerful than current gpus.
Choice is urs.
Dnt 4get 2 select d bst answer.