Crazy! I just played for 8 hrs straight and not one single issue.
I wish there was a profile for Rift. I get ~3% more FPS with the 2nd card enabled.
A few more tests in Skyrim:
31 fps 11a
34 fps 11b
39 fps when disabling the 2nd card.
3fps gain from 'a'. Nice. So glad I got 2 of these 6970's.
EDIT: In Skyrim
My headset (in L+R) goes mute when the SPDIF out is plugged in.
I switch to the SPDIF in windows out and sound comes out on my speakers.
~9% increase when crossfire is enabled.
FPS Setting, 1 card, 2 cards:
Ultra 70 & 77
High 86 & 97
Medium 100 & 108
Low 131 & 148
Min 153 &...
I have 4890x2 and 10.7 in XFire works fine. Both GPUS ulilized in BC2.