I am finally deciding to replace my old 6770 graphics card. I am almost decided on an rx 480, but do not know which version to get. I currently have an i7 3770k and z77 mobo. I am mainly looking to play higherish end games like bf1 ect. Should i get the 3,4 or 8gb version, and which is the best brand (asus, sapphire ect). Also, would the 470 be just as effective, and should i possibly consider the nvidia alternative? Thanks.