Vangar :
"AMD CrossFire Mode" and "FreeSync" and "Virtual Super Resolution" and "GPU Scaling"
Try to disable these settings if you have them on
There has got to be a better way, I have this same issue with my R9 295x2 on Battlefield 1 and although my main is due was trying to get a third R9 290 to run alongside it but out of everything i tried a few things actually made the card run smoother.
first being overclocking my processor (mostly helped my issues with trying to get the 3rd gpu but also increased stability with the 295x2 alone). the other thing that helped out alot was going into the bios on my ASUS Rampage V Extremeand went under "tweakers paridise" and changed the Gen3 preset to preset2, also the PCIe amplitude to higher. Doing This got my framerate to a solid 60fps at 4k on argon forest and monte grappa and in some areas of other maps but for some reason i get frametime spikes up into the 90's.
Another thing to try is something in battlefield 1 that everyone should do to utilize all their cpu and that is to create a notepad in the battlefield 1 directory where the bf1.exe is located naming it "user.cfg" and inside of the notepad named "user.cfg" write these lines
Thread.MaxProcessorCount 8
Thread.ProcessorCount 8
Thread.MinFreeProcessorCount 0
RenderDevice.RenderAheadLimit 2
GameTime.MaxVariableFps 59.94
(59.94 or whatever your own monitor refreshrate is 143.94/74.94 just .06 under)
Also a couple others that might help to just see where your performance is taking hits is to set acpu and gpu usage overlay and some more info on how many job threads and cores are being utilized along with how many gpu's are aswell by writing a couple more lines in the notepad
Render.DrawScreenInfo 1
PerfOverlay.DrawGraph 1
If anyone else has any tips on how to get these R9 295x2 cards running smooth please please post here like i did, i usualy dont post on these forums but us R9 295x2 owners need to help eachother out when we can because these cards are powerful but very temperamental and most of the time issues with them have workarounds to get them running smooth for certain games and so far Battlefield 1 has been the hardest game to do so, please dont hesitate if you have found a way as Myself and others have been struggling to have a good experience with this wonderful addition to the Battlefield franchise.