1080p on 4K display
I'm currently evaluating to buy a 4K computer screen to use in 2160p natively while coding or working with Windows but I plan to play my games in 1080p because 4K rendering is of course a very heavy job to do for any CPU&GPU. Currently I'm very happy with 1080p gaming and it would be great for me to have one single screen in those two modes.
However, I know that the upscaling algorithms are not just "1px in 1080p equals 2x2px in 2160p - so everything would be fine ..." as it is told in many forums. That's just wrong because normally the screen image gets blurred depending on the upscaling algorithms the GPU and/or the screen are applying.
Now, I stumbled upon nvidia's Dynamic Super Resolution technology and I wondered (but I could not really find out) whether it (or any other tech) can be used to tell the GPU to render a 2160p image exactly by bloating up a 1080p image to the doubled size per side . So that there's no need to interpolate any pixels and the 2160p-image would just look as crisp as the 1080p on a 1080p-screen (of course with the same non-4K-amount of detail).
Please have a look at the attached image I have stolen from http://linustechtips.com/ and extended with my comments:
EDIT: I know that DSR is supposed to perform downsampling high-res images to a lower-res screen. So it is the opposite of what I wanted to have. But maybe the nvidia driver can do the other way round as well (maybe it's not called DSR then but I don't know).
Best Answer
The DSR article is about a 1080 display benefitting from 4K rendering, which is the opposite of your use case.
The image is a fair idea, except that 1080 is 1920x1080 and 4k is 4096x2160. 4096/2 is NOT 1920.
For gaming, you're just going to want to use the monitor's native resolution so that the monitor doesn't tamper with the image.
Certain displays are able to do the pixel doubling.
The scaling is now simple pixel doubling at 1920x1080 so it so it renders well without the scaler messing with the image. This is better scaling (IMHO) for computer/game use which is what people running at 1080p@120hz would do.
That's the feature you're looking for: "pixel doubling". Stay away from bilinear or bicubic scaling.
Pictures about "1080p on 4K display"
Is it OK to use 1080p on a 4K monitor?
Yes, absolutely. You can definitely play games at 1080p resolution on a 4K monitor since 4K constitutes 4 times that of 1080p which can run games in 4K resolution much crisp and clear than the standard Full High Definition 1080p.Does 1080p look better on a 4K monitor?
Most 4K television set you bought can automatically upscale all the content you play on it. Obviously, full HD will continue to look better on it as compared to standard definition content. However, only a good scaling can make 1080p content look good on 4K TV.Can a 4K TV run 1080p?
Can 4K Ultra HD TVs play Full HD (1080p) content? Yes, 4K Ultra HD TVs can play Full HD content, but it won't be displayed in the standard 1920 x 1080 resolution we've all come to know and love. Instead, to fill the extra pixels that make up a 4K Ultra HD screen, the content first has to be upscaled.Integer Scaling - How to play crisp 1080p on 4k display (Windows 10)
Sources: Stack Exchange - This article follows the attribution requirements of Stack Exchange and is licensed under CC BY-SA 3.0.
Images: Dmitry Demidov, Timothy Paule II, NOHK, Arshad Sutar