[SOLVED] Help me understand rendering resolution and monitor's native output resolutions!

[aranorde]

I'm a not an expert in this, so if any of this sounds funny then please educate me.
Things are pretty complicated to explain so kindly take some time to read and reply, i might be over-explaining simple things here or under-explaining complicated things.
I will be listing a scenario/case and ask questions on it, it will be easy for me to explain and understand. Some questions may include sub-questions along with them, so please read them and help me understand this.

Scenario 1 (S1) : Rendering a game in 900p on a 900p native resolution monitor
Scenario 2 (S2) : Rendering that same game on 900p in a 1080p monitor.

Questions :

1. Will there be "any" performance difference between S1 and S2? (CPU usage / GPU usage / Frames Per Second)
2. In S2, Will my PC render 1600x900 (900p) pixels and up-scale the output on 1080p? OR do they render 1920x1080 pixels but in a down-sampled/down-scaled method? (I know this is the weird one)
3. If the game offers pixel-density options, then playing the game in S1 with 144% pixel-density (since 1080p is a 44% jump in pixel count from 900p) will perform same as playing it on 1080p on 1080p monitor?- And vice-versa when playing with reduced pixel-density to match 900p on a 1080p monitor? Will this out-put look same as playing 900p on 1080p?
4. What is the difference between pixel-density and render resolution when it comes to game settings?
5. Which out-put will "look" better between S1 and S2? (Pixel Density and Up-scaled output) (OR the difference in output matters on the monitor / game settings?)
6. What are the settings that I need to set high to bring the quality up if I'm playing like in S2? (Anti-Aliasing? Pixel Density?) Or is there any hardware specific feature on monitors that help to reduce the difference?

That is pretty much it, if you feel like you need to re-order the questions to answer them properly, please do ahead and do that but list them properly.

I'm pretty sure I'll ask follow-up questions if I do not understand properly, so please help me with replies as well.

Thanks a lot in advance!

 

[Eximo]

Not sure I've seen a setting for pixel density on anything, so not sure how to answer those ones.

Not sure there is enough information to answer your other questions, but I will give it a go.

1) Set resolution to 900p on a 1080p monitor
The GPU will render at the resolution that is set for gameplay. The scalar in the monitor will be taking the 900p input and upscaling it to 1080p so that it fits the display. Or it will not upscale and the image will be smaller than the screen. Some monitors have this option.

2) 900p on 900p is 'normal'. GPU will render, scalar in the monitor will not have to do much but convert the signal to the appropriate pixel colors as normal.

Under either circumstance the scalar is still doing the math to figure out the color of each pixel. But 900p on 1080p just isn't going to be perfect, which will decrease image quality.

Anti-aliasing will be done with the original rendering resolution, doesn't matter to the monitor it still takes the input signal and does its thing. AA will decrease performance, but may improve image clarity.

1:1 resolution with no scaling looks the best in my opinion.

 

[kerberos_20]

1) no difference in performance

2) it will get upscaled to 1080p

3) are u sure its 144% ?, seems to be 120% for 900p to 1080p
if we talk about this jump, then it should look similar to what u get on 1080p, perfomance wise it would be same, for downscaling from 1080p to 900p it will look slighly worse then on native 900p

4) pixel density (how many pixels per inch) is what u have on your screen, you can zoom on your monitor to see those tiny little squares, rendering resolution is resolution in which game gets rendered before it get down/up scaled for your monitor

5) S1 will look better on paper (depends on monitor quality and screen size ofc)

6) try to match native resolution first, if gpu has free horse power, u can use supersampling or rendering above your native resolution (nvidia dsr)