I have two Sapphire 2gb 5870's in crossfire. I can't seem to get the latest 11.3 drivers to install properly. I have the same problem every time. The screen flickers once during the installation, which is normal, then it flickers a second time and never comes back from black. I have to use the case power button to turn it off. Then it boots up like normal and shows the 11.3 drivers, but it doesn't behave properly at all when playing games. I've tried doing a clean wipe and installing the 11.3 drivers but have the same issue. I've also done a clean wipe (of Windows, btw!) and starting with 11.2. These drivers install with no problems, except I'm unable to activate crossfire. The option is simply ghosted out. MSI Afterburner shows the second gpu is "synchronized with the master" but I've tested in-game and the gpu usage shows 0%.
I read in another forum that it was best to start with 11.2 and then upgrade to 11.3 or the 11.4 preview drivers. So, I tried this with 11.3 and had the exact same problem. The screen flickered once, then flickered a second time and never came back from black. So, another clean wipe and I started with 11.2 then upgraded to 11.4 preview. This works, no lockup, and I am able to activate crossfire. Only issue is the 11.4 preview drivers are kinda wonky. My cards are always running hot, even blue screening at times. Dragon Age II has crazy texture pop ins that shouldn't be there (and weren't there with 11.3 drivers and a single gpu) on certain maps. I read in another post on tom's that the 11.3 drivers were great for 5870's in crossfire.
Does anybody have any idea how I can get the 11.3 drivers to work? Or possibly even better, to activate crossfire with the 11.2 drivers? Any and all help is greatly appreciated.
From what you said about 11.2 drivers graying out the option to enable crossfire, this leads me to believe that your cards may not be seated properly, or something is wrong with one of the cards or PCIe slot.
I also wouldn't worry about the 11.3 drivers if the 11.2 work.
I checked both cards and they are seated firmly in their pci-e lanes. They're each secured with 2 screws and I'm using 2 crossfire bridges. I tried the 11.3 drivers again with the same result. This time I left it on the black screen for 15 minutes. When I came back it was still on black so I used the power button to turn it off. When it booted back up I checked CCC and it shows the 11.3 drivers have been successfully installed. I've just been using this way so far without any issues. (Except one blue screen from gpu2 overheating, but that's unfortunately all too common) If it goes crazy again (probable) I'll report back.