I am having the vertical split screen with my 7900 XT on my 55" TV. I finally found a workaround that works! Firstly, i installed latest driver with amd. Then without DDU and in windows (not safemode) I installed V5-22.5.1-Rev5.0-PVN-UMD-WHQL-Nemesis-NimeZ-DCH drivers over the amd without uninstalling, i know this is not the way to do it but i just did it and it worked. Doing this may not be necessary at all but i just wanted to tell you guys what i did before finding a fix. I found a software called DisplayFusion and when you open it open Advanced settings then search for Disable WMI polling and then make sure fusion starts with windows.
Now when i start windows i get split screen but i let it load fusion and then i go to the back of my tv and unplug the hdmi, wait for about 5 sec (don't plug it in to quickly) then plug it in again, now you should have full screen. Now it should not get split again. Only sometimes some games do split it again, but all games i ran worked without splitting the image, but only half life 2 did that until i chose borderless window in the game then it stopped splitting the screen.
I'll tell you why i think its doing this. 2 amazing things happened because of this. 1 i have full-screen 1080p and the other mind-blowing change is that now everything is 100% quicker when alt-tab from a game, it does it in a split second!!!! and the response on the mouse is mind blowing!!!!! Even with vsync it's amazing!!! i think disable wmi polling has done something amazing that i think so many people don't know about and will because of this info go crazy on this software and buy it! This is the most amazing thing that happened to me in gaming ever! The response on the mouse is making me believe i am dreaming! I just cannot believe it. Now the aiming in red dead redemption 2 is amazing, i can now finally aim!! So my theory why the screen splits on some TVs, is that when you don't have this amazing effect of wmi disable polling it takes time for the screen to update information to the GPU with black screen when you alt tab or change resolution, that results in some kind of de-sync, i don't know exactly, but I'm almost positive the split second alt-tab and overall response is enabling it to work because now there is no delay. You guys have to try this, and even people without split screen issue MUST do this trick to get the most amazing response time ever! Please test this out and confirm without doing the installation of drivers like i did, stick to your current drivers and try the trick with fusion first!! If this works for you too, we need to get the word out about this trick! I still feel like i am dreaming because of the overall response with mouse and-tab out of games.
EDIT: There might be a chance it's a combination of one other trick i used, it's called "Automatically Disable Full-screen Optimizations" https://www.reddit.com/r/Windows10/comments/9t5be1/automatically_disable_fullscreen_optimizations/
It's a bat file and when you run it, it will give you options, chose the disable part and then apply! You can revert with the same bat file. It may be a combination of these 2 tricks. But when i used this bat file alone, i did not have all those benefits i talk about here, not by a long shot. But still, they might work best together to get the same amount of response as i have now. I had 1800 DPI on my G502 mouse, but after this i had to lower it to 550 because it was so fast and responsive now.
