I'm using Win7 and will upgrade to Win10 next year.
I bought a GTX 1070 to run games in 4K. Some run smooth @ 60FPS, others are barely able to sustain 30FPS.
Even though I wanna play games @ 4K, I'd rather go lower resolution to keep 60FPS. But of course I don't wanna play on a small window, I'd need some way to resize the game's window to fullscreen.
Is there any way to do it transparently to games? In example, set them to windowed mode @ 1080p and upscale the window to 4K?
Edit: Unfortinately playing games on fullscreen isn't an option. I really need to play them on windowed mode.
The best solution would also include making the window borderless, many games have that available but only on a "maximized borderless window", if it's not maximized its window gets a border. Some games make it even worse, forcing fullscreen when its window is maximized.
Best Answer
Fullscreenizer solution
One possible solution is to download Fullscreenizer (direct download), which is a free, portable, and open source tool for Windows. Using it, you can "Fullscreenize" a game (or any application), which forces it into a borderless window, stretched to fill your entire display.
It also has some other features which make it a better solution than native borderless windowed modes, such as preventing taskbar flickering and preventing popup notifications (optional).
How to use Fullscreenizer
You should set the render resolution to windowed 1080p (or your desired downscaled resolution) in your game and then "Fullscreenize" it once you've locked in your settings.
If you don't see your game or app on the list of programs, click "Refesh" in Fullscreenizer to refresh the list of running programs.
Why Fullscreenizer?
Games are inconsistent with how they handle fullscreen and borderless on lower resolutions, so that's why for this case we should rely on an OS-based solution and not a per-game solution.