Yeah had lots of problems with multi cards and eyefinity, running 3 6970's would just give me lag etc and crossfire never felt smooth, as for the Extreme4.. i had the 1st version and that worked OK on 2 cards but not 100% so i changed to a MSI P67 GD55 and all my problems went so I'm trying to find out if its a z68 or NF200 problem :s would love to use my Extreme7 board with eyefinity but it doesn't look like i can.