BioShock Infinite suggests that building an entry-level CrossFireX tandem isn’t a good idea: the average frame rate grows up but the bottom speed goes down.
Metro: Last Light
The CrossFireX tandem is somewhat better in this game:
There are no problems with the bottom speed whereas the average frame rate grows up just as expected.
The two Radeon HD 7790s are good in GRID 2, probably due to the overall optimization of the game engine for AMD GPUs.
Company of Heroes 2
Even with latest game patches and newest drivers, the CrossFireX technology just doesn’t work in Company of Heroes 2.
So, this is the only game in our review where AMD’s multi-GPU technology fails to work at all. Also in this game we can see the largest difference between the 1GB and 2GB Radeon HD 7790s.