With the latest Adrenalin and chipset drivers, I sometimes get a black screen when waking the monitor as well, not just the low 1280x800 resolution. I switched to HDMI (85Hz) now and will report back.
So interestingly, I am back on DP but stopped the monitor going to sleep and just used a screen saver and letting it lock the machine after 5 mins.
What I have noticed is that if you catch it soon enough, you can see the screensaver change res to 1200x800 and it runs for 1/2 second in the top left of the screen.
Now interestingly, when this happens, if I had any windows open at the time, they all resize to 1200x800 instead of half and half on the screen, however the res stays at 3440x1440 so its not causing the res issue. It does this on any driver with the screen saver. I am starting to think this is something to do with either the Picture in Picture that the panel can do or there is some weird display issue with the firmware/panel.
It'll do for now as I am gaming on this and want the 144hz but if I wasn't a gamer I reckon I'd just sit on HDMI and 85hz
I also installed the KB4598291-Optional patch for Windows 10 as it fixes the following among other fixes:
- Updates an issue that displays a blank lock screen after a device wakes up from Hibernate.
Unfortunately it didn't help. I will also try a clean Windows reinstall as I haven't in about two years.
I also ordered a high quality (VESA certified) DisplayPort 1.4 cable and will test as well. I will also test with an Nvidia GPU, as the original poster mentioned he couldn't reproduce the issue with an RTX 3080 card.
I can also confirm that hdmi works without any black screen issues but all DP ports I can’t even get past windows start up n screen crashes. I’m using a msi ultrawide, on a new build pc of 5900x and msi rx6800xt trio! My old rig of 3600 and msi 1660super has no issues at all, so it’s all a Amd software problem. Only had this gpu for a week and countless problems from installation to black screens and as some of you guys have said it just doesn’t go well with ultrawide screen for some reason. Tested on tv with hdmi and can confirm no crashes or black screens and everything is fine too!
I got a GTX 970 and will try to test it as soon as possible. Can't use my PC as I have it water cooled and use hard tubes. I have enough other components so I can build a test rig and give it a go.
Although it does indeed look more and more as a driver issue and AMD needs to fix it.