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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: enter image description here

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).

  • Actually, Nvidia's DSR tricks the game into believing your screen has a higher resolution than it really has. It therefore allows you to play at a higher resolution, and downsamples the graphics to fit your screen. In your case, DSR would allow you to play at 5431x 3055 or 7680x4320. – Nolonar Aug 23 '15 at 13:31
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    You should be able to tell your video card to scale render 1080p graphics to 2160p on output, but I don't think you'll have any control over the filtering used. It possible though that your video card is already doing this, so you might want see if you can't disable this in the video card and see if the display does a better job. Also consider the fact if you're not playing old pixel graphics style games, you're not starting with "crisp" 1080p graphics. The edges will already be blurred (through various anti-aliasing techniques), and a simple 1:2 scaling will exaggerate that. – user86571 Aug 23 '15 at 16:09
  • What makes you think that upscaling 1080p to 2160p will be blurred? Do you have any sources claiming that there is some sort of upscaling filtering applied? I know people who claim that 720p on a 1440p screen is as crisp as 1440p; Why would this be any different? – Elise Aug 23 '15 at 17:32
  • I read it on some testing sites like this one (see "interpolation and upscaling" at the last third of the article): pcmonitors.info/reviews/asus-pb279q – Waescher Aug 23 '15 at 17:49
  • @Chippies. I was wondering about that too, so I launched Half-Life 2 in 1080p on my 4k screen. To my own surprise, I realized the image really is blurry. – Nolonar Aug 26 '15 at 11:06
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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.

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    Sorry, that was my fault: I aim to a screen which as the resolution of 3840 x 2160 so it is exactly the supeior of 1920x1080. And I know about that opposite intention of DSR but maybe it is possible as well. Seems not to be the case ... – Waescher Aug 23 '15 at 13:30
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Okay, this topic seemed to be harder to illuminate than I ever had thought. So I just bought the UHD screen I talked about and I can give you my sight on this topic:

Gaming on 1080p is not a big deal and I find the results quite good on my screen (Dell P2715Q). It seems not to be blurry - at least not that it would bother me. Gaming on 2160p just looks gorgeous but that was no question to me. By the way I had a looong discussion with nVidia about the pixel doubling I wanted to have but they have no option to achieve this. At least they want to investigate it but I don't know if this was just a default phrase.

The real downside is not the gaming at all. The scaling of the desktop applications is the real problem for me. Most of the non-Modern-UI applications fail at rendering with DPI-scale. Running the desktop mode with 1080p could help here but this is not why I bought a UHD screen.

I love the screen and I think I can get used to the scaling in windows but I'd say that anyone who's thinking about a 4k screen should think more if he'd can go with DPI-scaling than about if a game looks good on 1080p.

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