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:
- Download and install the Samsung CF792 latest driver here > http://www.samsung.com/us/support/owners/product/curved-monitor-cf791-series
- Start the games that give you a black screen.
- Once the black screen appears, press Alt+ Tab. This enables Windowed mode, you should get a picture.
- Navigate to the video menu, drop the resolution down to 1920x1080 Windowed mode, apply.
- Same again, but select full screen mode and apply.
- At this stage the screen may go black again, or it may work correctly from here on. It varies from game to game.
- Assuming it works okay, go ahead and Apply 3440x1440@100HZ. Quit the game normally, do not Alt+F4.
- If it does not work, apply 2560x1440 full screen. That should work, if it does repeat step 7 and quit the game.
It's strange, but this works for me.
I had the same issue with Vega 64, DP 1.2a ACer XG270HU. IT is the displayport! change to HDMI 2.0 cable and the problem is gone! I had the issues with Prey and Far Cry 4. I really hope this solves both your issues.
With some testing this work around seemed to work some games but not for all, PUBG seems to be very finicky with this, I have to do some more testing once I have time. But for now I have the most problems with PUBG and Hellblade: Senua's Sacrifice(which I got working for a while but after a restart I had to do the workaround again), which both are Unreal 4 engine games, this makes me wonder if it is a problem in the drivers.
I tried HDMI 2.0 and it seems to work OK regarding the black screen issue, however with the HDMI 2.0 I do get the freesync flickering that has plagued this display and with DP I do not (when it works), so I would rather find a way to fix the DP issues if possible .
For now I have ordered a new VESA certified DP1.2 cable from Accell to see if replacing the cable could work, because I noticed that when this black screen issue happens and I alt-tab, sometimes it gives the Display Link error, so hopefully replacing the cable could fix it.
I tried with a certified DP cable, same issues persists.
It seems that same games work ok if launched in windowed mode and changed in game to fullscreen mode, however I need to do this every startup otherwise I get the signal loss issues, for now I am mostly able to work around this issue.
Hopefully it is just a software issue and we do get a driver fix.
I have same issue but i m using fury nitro.My simple solution for you is to try using freesync windmill demo before you start games and you wont get black screen anymore.However some games are unfixable at the moment like Senua and Mass Effect:Andromeda.Well, you can play it with Freesync disabled.The problem happened when they introduced 17.7.2 although even before black screen happened but not really often.Now there is no flickering , but Freesync causes black screen and doesnt really work correctly because tearing is quite obvious sometimes.
amdmatt@ does Amd know about this issue? How hard is it to test this, especially when they offered bundles with vega and cf791?!It must be something wrong with freesync because when it's disabled all problems dissapear with black screen. It is frustrating to have problems like this when you pay alot for top products.
Yes Fury X and acer 144hz XG270HU screen, the issue is HUGE with 17.7.2 and less affecting with 17.4.3.
I cannot use anything other than DP since the HDMI1 of fury doesn't support freesync
I have raised a ticket with our engineering department to try and reproduce the issue, for now use the workaround i posted.
Although it is not ideal, it has so far worked in every game i have tested.
Thanks, the workaround worked, at least in battlefield one for me
Same problem here with allmost the same setup (1700x, tridentz 3200mhz cl14, asus prime x370-pro, corsair ax860, Vega 64 liquid and cf791.)
I got mass effect andromeda working by turning monitor off and back on again, but there are some flicker after that and havent played for more then 15min, but with freesync on the monitor would turn it self off and on every 5sec
When spending over 3000€ on your pc you dont think there would be problems like this
Using samsung c34f791 with the ultimate engine (tried standard, but problem was the same) and dp-cable is the one that came with the monitor.
First the flicker and now less flicker, but with black screens/monitor turning itself off...
If i knew i cant use freesync with this monitor and the best amd card then i would have gotten 1080ti+g-syng for the same price becourse vegas prices...
maybe will be fixed, it's in patch notes in the new drivers:
- A limited number of displays may exhibit brief signal loss periodically.
You heard back from them on this? Black screen on my R9 Nano with the same monitor as well.
No update yet folks, sorry.
Another workaround is to use a HDMI connection. This monitor supports FreeSync over DP and HDMI.
Little update, the workaround don't work on latest drivers, many signal losses even in windows with 17.11.1
(Workaround works in 17.7.2 not so well after)
It still works for me.
Here's the exact steps i take.
1. Start up game, black screen. Press Alt Tab.
2. Navigate to the video menu, use a lower resolution and set it to full screen mode.
3. Black screen, press Alt Tab.
4. Repeat step 2, no black screen this time.
5. Repeat step 2 but set 3440x1440, save and exit game.
6. Issue resolved until i reinstall driver, driver crashes, or i enable/disable HBCC.