ok i just got another 7970 to crossfire but i wanted to reinstall windows. but now my first 7970 works fine till i install 12.10 and reboot. the second card works though but whenever i use them both in crossfire or only the first card i get a blue screen, artifacts when windows does load or it freezes when the windows logo shows up. ive tried switching the cards pcie. the same thing. ive made sure its not the psu or ram and i put the cpu(2500k) back at stock speed. all i can think of is a bad version of winfdows or some how in a day my 1st card died.....
More aboutcatalyst problem help
You can try 12.11. You also might want to try to switch them.
What power supply are you running? Are you using the Crossfire bridge?