I recently RMA'd two 7970's to XFX as I was upset about the voltage being locked on the two I had. XFX was kind enough to offer to replace them for two with reference PCB's and unlocked voltage. I have the cards back now, but they do not seem to working.
At first my computer would not even load windows with the cards installed, but it loaded fine without them installed. I tried each card individually and together. I also tried different PCIe slots with the individual cards and still had the same result.
I used a driver sweeper to remove all AMD drivers and reinstalled. That allowed windows to load, but the cards still do not work. I have tried every driver version from 12.3 to current and all have the same results.
In device manager there is an exclamation point and error 31. I let windows scan for the updated drivers, but it tells me the drivers are the most up to date version.
I have also reinstalled windows and that had no effect on the problem.
Both cards are recognized and I get a video output from them, but that is it. GPU-z shows the default clock and memory speeds at 1000&1425, but the current speeds are 0 & 0. I also cannot open CCC as it says there are no setting that can be configured with CCC.
I have opened a ticket with XFX, but am waiting for a response. Can anyone offer some more guidance?