DPI scaling: is it all Windows, or are GPU driver & monitor involved?

[Jumpem]

It seems most of the discussion focuses on how Windows handles DPI scaling. Is that only for the desktop and non-game applications?

Does the video card driver or monitor come into play?

 

[PrincessFrosty]

It looks like windows handles scaling when it comes to the desktop, not just scaling DPI but also scaling non-native screen resolutions to fit your monitor.

For games and 3D applications the drivers take over and at least in the case of Nvidia you can select how the driver handles scaling, it can do it on the GPU which gives you several options of how you want to handle scaling non-native resolutions (black bars, stretching, etc) or you can simply pass the original output to the monitor and let the monitors scaler deal with it, that depends on the monitor and what features it supports.

Just from my own testing, windows handles scaling fairly badly, even when it's 1080p -> 4k which gives you a perfect 4:1 scaling (pixel perfect scaling) it can't handle that correctly and you get degraded quality.

It seems to be somewhat of a concern especially now we have 4k monitors and unless you're at 32"+ you'll probably need to use some kind of scaling.

 

[Flapdrol1337]

My guess: If you set windows to 4K and increase the dpi windows handles the scaling. Otherwise the gpu or monitor will, depending on what you configure in the driver.

 

[Jumpem]

4K is why I am asking. I would like to get a 4K monitor. and it would be relatively small as all of the G-Sync capable versions appear to be 27-28 inches.

I want to be able to increase the size of the desktop fonts and buttons. Roughly make everything still appear as it does with 1920 x 1080, but with the increased PPI of the 3840 x 2160 resolution. I also have interest in gaming at 4K with say Diablo 3, and then gaming at 1920 x 1080 for demanding games.

 

[bystander36]

When it comes to scaling the overall size of what is seen, you have the choice of using the GPU or displays built in scaling, but all that does is stretch or shrink the frames to fit, or not fit the screen.

As far as button and icon sizing, that is where problems arise. Windows handles desktop stuff, and allows you to adjust sizing, but specific applications may or may not be programmed to allow Windows to adjust the size of their buttons and text.

Games handle the sizing of their UI completely on their own. Many if not most will not resize the UI for your resolution, though it is becoming more common that they do resize or allow you to resize it with a slider.