Crossfire HD 6950 Troubles?

Recently, I bought an additional PowerColor AX6950 2GBD5-2DH Radeon HD 6950 to crossfire. It seems that it's operating okay apart from once I try to play a game title I get a BSOD. The entire system was assembled May however I also just brought my system board up-to-date(because of failing SATA connection) and also got a brand new CPU heat sink to ensure that I'm able to overclock when I have worked al the kinks out. In any event, specifications are listed below:

Case: Cooler Master Centurion 5 II

OS: Home windows 7 Ultamate 64bit

CPU: Intel i7-960

Heat sink: Nuctua NH-U9B

Mainboard: ASUS Rampage III Formula

RAM: 2x 8gb Kingston DDR 3 2200MHz

Graphics Card: 2x PowerColor AX6950 2GBD5-2DH Radeon HD 6950

HD: OCZ Vertex III SSD 120gb SLD3-25SAT3-120G (Primary)

HD: Western Digital Black 2tb (Secondary)

PS: OCZ fatal1ty 750 Watts

After I switched my mainboard out I did not re-install windows 7 Ultimate because I did not think that might be an issue because of same chipset and I'd approach that only as a last measure to ascertain if that fixes the issue. I searched all over the net and i can't find anything relating to this problem. I have re-installed the system drivers, both cards work correctly when I have checked them individually as well as the board seems to identify both cards in crossfire mode within the Windows System Information (2GB of devoted graphics memory). Any assistance or suggestions will be vastly highly valued!

Crossfire HD 6870 issues?

Did you considering it might be a Windows driver problem?

I think you may require another driver for crossfire to operate properly!

Crossfire HD 6870 issues?

I would definitely re-install Windows 7!

However, I'd visits the motherboard manufacturer's (Asus in your case) homepage, download and flash the board with the latest bios version as well as install the most recent chipset driver.

Crossfire HD 6870 issues?

Okay...Windows re-install following a system board change is essential. Especially if the boards have 2 Individuals chipsets.

Re-install Windows 7 and install Amd latest CAP1 and you ought to be okay.

Its very rare...and I've switched out 60-70 mainboards, that windows 7 would still work after a board change, I received plenty of BSODs particularly during video games. Simply a new Windows installation and they were running great.

Alright well I am about to re-install windows (it has become a problem because of the brand new system board and its just an OEM copy of Windows 7). I had been told after I bought the brand new system board that than my old board was exactly the same chipset and so I would not have to re-install Windows. I genuinely thought these were distinctive chipsets to start with, however I was not convinced and the sales rep who helped me made me uncertainty myself lol...Will not likely be going there again! Thanks a lot fellas!

Its always best to reinstall windows when you change your motherboard. Its also gives you a chance to clean things up!