I have a Radeon 6870 by Powercolor (stock cooler) for a while, and I've decided to get another one to put it into crossfire (didn't have enough cash to upgrade to r9 card). However, the card that I bought (HIS 6870 IceQ Turbo X) keeps crashing in game and I don't know why. The Powercolor one works fine except it is heating up a lot (like 100+ degrees) so it is in service for a clean-up and new thermal paste (couldn't open it myself because of warranty issues). But even when the Powercolor one is overheating it is working fine, while the HIS one keeps crashing my PC.
My PC specs are:
Gigabyte 990FXA-UD3 mobo
HIS Radeon 6870 IceQ Turbo X gpu at stock
Corsair Vengeance 2x4gb ram at 2133 Mhz
AMD FX-8350 Cpu at stock
Samsung SSD 840 EVO 120gb
Raidmax 835watt RX-835AP 80plus bronze PSU
Windows 8.1 x64 os
Just to be clear, the problem isn't with the crossfire, the card itself is crashing, while the other one is ok. No error messages are showing after booting up and the temps are around 40 degrees Celsius idle and 60 in-game (until it crashes). Uniengine Heaven benchmark is also crashing it. I've uninstalled the drivers with guru3d tool and still nothing. Just freezes in-game and sends my monitor in power saving mode and in the background is some buzzing sounds. Sometimes it doesn't send my monitor in power saving mode but it crashes the game and recovers the driver, but the reinstall doesn't help it. And some games like NBA 2k14, League of Legends, CS:GO are working perfectly with it but in TERA: Rising, Far Cry 3 and other more demanding games it crashes. Thx for the help!