6gb of VRam are absolutely worthless.  You will never use it in gaming before the card itself is obsolete, and you will never use it in bitcoin/altcoin mining. 


Get this instead:

http://www.newegg.com/Product/Product.aspx?Item=N82E16814202008&nm_mc=EMC-IGNEFL061413&cm_mmc=EMC-IGNEFL061413-_-EMC-061413-Index-_-DesktopGraphicsVideoCards-_-14202008-L04D