Read TFM for your motherboard. Look at ALL your info in BIOS.
Swap cards in your PCI-e slots. Does your mobo have an auxiliary power connection for CrossfireX?
More power in Catalyst? Manual adjustment of fan speeds? Core clocks and memory clocks manually adjusted?
CrossfireX not required nor beneficial on many games.
You have not posted your system specs so have no idea if you updated your BIOS on your mystery motherboard.
Swap the "other" bridge that you have.
Case airflow configuration?
Cpu? Temps? Cooling method?
"Dust free and clean"? Have you ever cleaned EVERY surface and fanblade in your PC?
Do not reinstall Windows unless your system is completely locked up!
02:40 PM by