Hi Tom's Hardware! I've been an avid lurker of your site for many a years and I finally have a problem of my own.
I recently received a very expensive desktop via Alienware. The person who purchased this for me had bought the same exact system with 1 difference. The video cards. He chose x2 480s when I chose 2 5970s. He was complaining about the drivers a lot so I thought "Well, if nVidia can't get it straight maybe ATI will."
I've been sitting on this pc for about a week unable to do much anything due to catastrophic driver issues. I have never in my life dealt with such issues (having used nVidia for the past 8ish years).
Enough of all that, my issue is that my computer came pre-installed with outdated drivers (I cannot remember what version) so I immediately downloaded and attempted to install the newest version (10.11) but was unable to open CCC. I followed this a remedy from this thread from a post by chris-ch and I can open CCC again.
But it seems my problems are not even close to being fixed. I spent about 3 hours with Alienware tech support letting them control my system & reinstall the same drivers again & again expecting different results (isn't that the definition of insanity?). I said to hell with that and have come here knowing what the community of Tom's Hardware has to offer.
Here are images from GPU-Z showing Crossfire isn't enabled yet it is via CCC. Also, you can see that GPU #2 & GPU #4 have different drivers than GPU #1 & GPU #3
On another note, I tried to rollback to 10.10 and I get an error message saying something about how I don't have a compatible GPU. Not sure what that's about.
This is really strange, I've never seen anything like it, the only thing that I could suggest is to either try removing ALL Ati drivers with driver sweeper then reinstalling 10.11 OR try maybe reinstalling windows and see if that has an effect? Maybe try taking out one card and fixing one at a time might help as well?
Check your crossfire bridge. It could have come loose or have been damaged during shipping. You may want to borrow one from a friend if they have one they never used. If it's not the bridge make sure both cards are properly seated and have the power connectors fully inserted. Also, try the cards individually. Test one card, then the other to make sure they are working fine by themselves and producing the proper results.
If it's not a hardware problem then it may be best to simply format the machine and re-install the OS. Personally I would just format it before taking it apart ^_^