Nvidia Inspector SGSSAA vs Inspector OGSSAA vs Downsampling OGSSA

I am trying to find the best method of anti-aliasing with the least amount of performance impact.

http://naturalviolence.webs.com/nvidia.htm

After experiementing, with Nvidia inspector, down-sampling and the other AA options. I want to hear other people's feedback on this who have knowledge of anti-aliasing.

Does using down-sampling OGSSAA offer any benefits over using HSAA or OGSSAA from Nvidia Inspector?

Someone told me using the down-sampling method creates more pixels on your screen, is this true? Does OGSSAA from Nvidia Inspector do the same with more pixels even tho you are not running it in a higher resolution in game?

If you can just use custom resolution's with down-sampling method for monitors, then why would you buy a 27 inch 2560x1440 monitor when you can just down-sample a 27 inch 1920x1080 monitor to the same resolution?

Alright done with the questions, in my experience after using all methods, I still notice some jagged edges, they are very very small, but still present no matter how high of a resolution or how high of super-sampling I use (Yes, I tried both sparse grid and ordered grid). And after a certain point, increasing the amount of anti-aliasing doesn't seem to have a effect on the image quality, it only degrades performance.

Which way is the best performance and picture?

 

Downsampling means rendering an image at a higher resolution than the display and then reducing it to a lower one with reduced alias being one of the benefits. This means that the GPU is doing the same amount of work it would do if it was actually displaying it at the higher resolution.

A 2560x1440 display contains 78% more pixels than a 1920x1080 one, which means it can show more detail and the image will look sharper and less pixellated from the same viewing distance on a 27" screen. The advantage is that a 27" 1920x1080 display would require less GPU power to run games but given the choice I personally would much rather have a 2560x1440 resolution with no AA if I had to choose a 27" display.

 

I know what downsampling does, but downsampling will not increase more pixels onto my monitor right? Unless I buy a display with native 2560x1440, downsampling only helps to remove aliasing, but will not offer more pixel increase? Is that what you are saying?

I've tried all various methods of reducing aliasing. I am now sticking with the downsampling OGSSAA method because I think there are more pixels in-game. Maybe I am hallucinating but the picture seems more crisp than using Nvidia Inspector's Super-sampling alternatives when at 1920x1080 ingame resolution. Maybe it depends on the game, this is a really old game, Battlefield 2, maybe the developers didn't optimize the pixels in relation to newer displays, and that's why I am seeing more crisp of a picture at a higher in-game resolution. I swear there are more pixels on screen after I down-sampled 2560x1440 ingame to my monitor native 1920x1080 resolution.

Or am I wrong and downsampling can increase pixels on your display? If this is true, I am still wondering what is the point of buying a native display with 2560x1440 res, if I can just down-sample it from a 1920x1080.

 

Yes, a display cannot show more pixels than its native resolution offers.
A common misconception is that downsampling from 2560x1440 to 1080p has the same effect as rendering the image on a native 2560x1440 display of the same size, which is wrong. Downsampling (OGSSAA) reduces aliasing, it's an inefficient brute force attempt with a suboptimal pattern, but it's better than nothing when nothing else works. Native rendering on a high resolution display isn't anywhere close regarding aliasing. There are (or have been, modern MGPU systems can handle high resolutions) many people using lower than native resolutions so they could apply antialiasing, which quality wise worked out better in the end.

 

Alright, that makes sense.

Nvidia Inspector offers OGSSAA through their super-sampling options along with SGSSAA.

OGSSAA
1x2 SSAA (2xSSAA)
2x1 SSAA (2xSSAA)
2x2 SSAA (4xSSAA)
3x3 SSAA (9xSSAA)
4x4 SSAA (16xSSAA)

Which one do you believe would carry less of a performance hit? Using these anti-aliasing methods through Nvidia Inspector or just down-sampling using a higher but custom resolution?

I'm not understanding how super-sampling is being done when using Nvidia Inspector. Does 1x2 SSAA mean that horizontally the image is being stretched longer than the original, while the vertical remains the same in order to remove jagged edges? I assume 2x2 SSAA means the image is double the size, basically the same as using a custom resolution twice of 1920x1080 (3840x2160) then the resolution is down-sampled to that of the native resolution?

 

Downsampling will give you far better image quality than running FXAA. I run many DX11 games downsampled from 1600p to 1200p and the results are excellent. Here is a screenshot from Bioshock Infinite running 1600p, everything maxed.

 

I'm not sure why you quoted me here, I didn't say anything about FXAA? Post AA in general is a crutch (although SMAA works better than the usual FXAA implementations).

 

While it might look nice in screenshots, on display downsampling can look rather bad. SGSSAA is superior option if you can pick it (it also has much better sample pattern).

 

It honestly depends on the game. AND your personal preferences.

You will have to experiment to find the solution that works for you. There is no 1 that will be a constant.


Downsampling+in game Post_AA(Preferrably FXAA TBH, SMAA 1x doesn't work for crap with downsampling in my experience) can many times bring better IQ, AA and performance than other methods. But it just depends on the game. Often SGSSAA is the most temporally stable and is near alias free. But it will sometimes lean on the blurry side for too many people.

OGSSAA Hybrid, when a game supports it and you have the power, often provides the best IQ of all.

8xS with 2xSGSSAA or 8xSQ with 4xSGSSAA looks amazing.


Other times, your only option is to downsample if a game is DX11 only and only offers post-AA (Like Strike Suit Zero/Infinity)

https://i.minus.com/ibhKZVlLOcYEEx.png
https://i.minus.com/ibkHErA9UOQcSJ.png

 

What are the timings options in the Nvidia Create a Custom Resolution? Can messing with them damage your display even though you are not going above your pixel clock?

 

It's a risk you take. Though as long as you don't use any 3rd party tools to adjust the pixel clock higher, you should be ok.

 

Try this guide. Much easier than playing with the manual settings that can FUBAR your display.

http://www.neogaf.com/forum/showthread.php?t=509076

 

Ok so you can mess up your display with manual timings? I just don't understand why in the downsampling guide on Guru3d. He tells you to lower the vertical total pixels and increase the horizontal pixels as high as possible before getting over the limitation of the pixel clock.

On automatic timings my settings were low as possible and my pixel clock was only 148mhz. I thought because my total pixels on both vertical and horizontal were lower than his from the guide. I was getting worst of a image quality. I increased it to match his guide and now I am afraid I damaged something because it was higher than what my automatic timings settings recommended.