I tried to overclock one card with crossfire disabled for star wars battlefront in the profile only.What happens is the overclock is then set to the global settings.So its set for everything else too not just swbf. So i just reset and run it stock. I have to run one card because on sw battlefront X-fire needs some support.But i do get the cross-fire disable to work. I browse to the .exe file and apply it and its set. Found that tip in some forums.
16g ram 1333
2 gigabyte 7970's non-gighz editions
850 corsair psu