I have a trouble with Samsung CF591 monitor setting attribute as FreeSync 'Ultimate Engine'. Once I play steam games (Tales of Berseria or Mighty No.9) in a certain time, the computer suddenly crash and self-restart. I tried many AMD drivers (16.11.5, 17.8.2, 17.11.1, 17.11.4, 17.12.2, 18.1.1alpha), but it still gets randomly crash. After I change setting to be 'Standard Engine' using AMD driver 17.8.2, everything works fine. Hope this issue will be resolved in the upcoming AMD driver.
AMD driver setting : AMD Freesync on, HDMI Link assurance on, AMD Fluid Motion Video on, Frame Rate Target Control 72FPS
Display setting : Screen Refresh Rate 72Hz
In-Game setting : Frame rate 60FPS
Computer Specs
XFX RX480 GTR Black 8GB
Intel i5 6500
RAM 8GB*2 3200MHz OC
MSI Z170I Pro AC
This link from AMD Forum might be better suited for your problem: CF791 Freesync black screen via DP
This an answer that AMD_MATT gave about a work around using a VEGA64 GPU card. Don't know if it will work for your or not from the above mentioned link:
amdmatt
Sep 13, 2017 10:02 AM (in response to vese)
I have the same monitor and Vega 64 GPU and experience the same issue. I'm not sure what the cause is here, but here's how you get around it. Once you do this trick once, you should not need to do it again unless you reinstall the drivers.
Once you have installed the latest compatible driver and restarted your system:
It's strange, but this works for me.
This was the "Correct Answer" from above mentioned link:
Correct Answerby amdmatt
on Dec 20, 2017 2:07 AM
This issue is now resolved in 17.12.2 folks.
Radeon Software Adrenalin Edition 17.12.2 Release Notes
Resolved Issues
This is another link concerning Samsung Freesync connected via HDMI. It doesn't mention black screens or crashes but it is informative about other problems using Freesync on Samsung monitors.https://www.reddit.com/r/ultrawidemasterrace/comments/5m2bgh/just_received_samsung_cf791_monitor_major_problem/
Otherwise I would send in a "AMD REPORT ISSUE" to let AMD know it still has problems.