Displaying a game in 2560x1440 on a 3840×2160 native panel.

So I'll be getting a 4K UHD panel soon, with native resolution of 3840×2160.
Assuming that I can't quite push games in full details at that resolution, I will be playing mostly in 2560x1440.

But I'm thinking, if the game is internally rendering an image at 2560x1440 pixels, and then upscaling it to 3840×2160, won't that result in a distorted image? Because 3840×2160 is 1.5 times 2560x1440, so that should mean that to fill the screen of a 3840×2160 panel, only 1 in 2 pixels of the image rendered at 2560x1440 will be repeated twice. Isn't that right? And doesn't that distort the image? Because it's not an even upscale. For example if we display an image rendered at 1920x1080 on a 3840×2160 panel, then each pixel is repeated twice (both veritically and horizontally, so it becomes a 2x2 pixel area), and there's on problem. But that's not the case with 2560x1440. This sounds complex to visualize so I made a little image to represent it:




So how is this distortion issue avoided?

 

The dp is so fine, I can barely tell in a game, even when I get in close and go looking for it. 4k on 17" is 260ppi or 10px/mm, this overkill is more than enough to hide the scaling issues at a normal viewing distance

At windows desktop, it is noticeable on some text, especially small/fine text

Sent from my Redmi Note 8 Pro using Tapatalk

 

Play at 1080p, and assuming you have an NVIDIA GPU based on the Turing architecture (RTX, GTX 16XX), enable integer scaling from the driver control panel. This essentially makes the game look like it is running at 1080p without any of the interpolation that occurs when using an LCD at something other than its native resolution.

 

I don't think there's any problems playing on 1080p on a 2160p native screen, since the scaling is done properly, 1:2.
The problem is upscaling 1440p to 2160p, since in that case only some pixels get doubled, so the image is overall distorted.
Playing at 1080p is not a solution for me. Since the hardware is capable, I'd like to render at least at 1440p.

 

There is some blurring with 1440p, but there is still more detail a running 4k screen at 1440p than running 1080p on a 1080p screen.

 

Why not get a 1440p panel instead? Or upgrade your GPU to be able to render in 4K satisfactorily? Anything else sounds like a compromise you are not willing to make.

 

To be honest, right now even the 2080 Super can't properly deliver all games at max settings and 4K.
There's only two choices for the panel, 1080 or 4k. I'm not sticking to 1080p for another 5 years so definitely going for the 4K panel.

 

. . . how about 1080 SLI . . . (had to say it lol)

But in all seriousness, I'm sure they make 17" 1440p panels that you should be able to swap in. What computer?

 

That's okay, I actually want a 4K regardless, I'm just puzzled that 1440p doesn't scale properly and I'm surprised there's no fix for it.

 

1440p 17.3" panels do exist. The P870 series had one available for a while. You'd have to switch the panel yourself though. idk if the cable connectors would match. 1440p should still be 4 channel eDP for a 40 pin connector, but older connectors were all .5mm pitch connectors, while some newer ones are .4mm pitch.

 

This is the best solution.

 

In that case, you want to enable GPU Scaling from within the Image Sharpening setting in Nvidia Control Panel. This will use a higher quality upscaler and apply sharpening to improve clarity when using non-integer sub-native resolutions.

 

Interpolation of non-native resolutions is a drawback of LCD displays. The newest and ultimate upscaling technique, only supported on RTX GPUs, is DLSS 2.0, which uses the Tensor Cores and trained data, to upscale from a lower resolution that actually improves image quality over native resolution. For example, 4K with DLSS 2.0 upscales from an internal resolution of 1440p while looking better than native 4K with no upscaling. Not all games support DLSS 2.0, but for the ones which do, such as Death Stranding and Control, the result is phenomenal, and it's a huge boost to performance on top of improving image quality.

 

Now this is information that is useful.

 

Ive tried different scaling resolutions on none native panels. in short it works but it only looks good if your doing 1:2 scaling. 1080p on 4k, or 540p on 1080p, etc. What I would really like is a panel that can scale pixel clock linearly with resolution. So if I can do 60hz on a 4k panel, I would like to be able to down scale and do 1080p at 240hz. Same pixel bandwidth, just my choice of resolution or refresh rate.