I don't think this is normal... (AMD crossfire)

I'm currently running an eyefinity 5720x1080 set up, but I've noticed (obviously) that running it off a single gpu (XFX AMD 6970) runs much, much, MUCH better than running it off crossfirex (6970 x 2). Hell, even the temperature stays significantly cooler. Whereas crossfire causes both my gpus to spike above 90c under the slightest load, running it off a single gpu has it consistently staying under 80c even under heavy stress.

What could be the problem, reddit? I always hear people with great success stories, so why is it doing the opposite for me? For instance, FEAR 3 runs at a smooth 60 fps consistently running single, whereas crossfire drops its fps horribly, coupled with unbearable stuttering. Same for WoW, and even ToR.

Any help would be much appreciated! And I've tried reinstalling drivers, I have the latest application profiles, etc etc. I've been researching this for weeks to no avail, so I've turned to the best experts I know online. Again, thanks in advance for any inputs!