The game does not support CrossfireX for Multi-GPU.
Does Bohemia intending to work with AMD and Nvidia to support the ever growing population of dual GPU systems?
There's a fix available under the forums however it uses an Arma 2 profile and it adds little to no performance benefits currently.
Enable CrossfireX in CCC and run the game - 0% usage on the 2nd GFX card unless you enable arma2 profile in which case both cards used but it is not optimised and runs as though you had 1 card.
before raising this i've searched for 'crossfirex' 'crossfire' 'SLI' 'multi gpu' but nothing has been returned in the search results.
Are you sure that you have set the correct crossfire configuration? I have played with SLI since day one. And I have yet seen any problems with it and both scale decent.
Categorically - Yes.
http://forums.dayzgame.com/index.php?/topic/157429-slicrossfire-support/
i've explored this in great detail.
kakan - Try running one card then try two. There is no performance gains. This is documented by hundreds of people trying to increase their FPS through the use of the 2nd card and the Game and the eyefinity profiles literally don't support it at the moment.
Running 2x XFX R9 290X in Crossfire, forcing DayZ.exe with ARMA2 profile causes the FPS to drop about 10-20 fps average. Single card seems to outperform, however while streaming the Crossfire seems to maintain better performance over the single card. ARMA3 looks beautiful on Ultra, I hope that DayZ SA can support Crossfire and gets good optimization soon.