Nvidia and dithering controls..how to enable?

It works, Windows just randomly breaks gamma ramps precision. Try changing resolution once via Nvidia Control Panel after changing the registry keys and restart.

 

Tried that and still nothing. I can still see color banding in here and here.

 

Because these are 8 bit pictures, banding is already in the sources. Dithering can't fix that. In desktop usage, dithering only helps to prevent additional banding when applying GPU gamma ramp adjustment with enough precision (driver color options or loading 1D LUT via DisplayCal loader or Calibration Tools).

 

Whatever the case, I saw no difference anywhere. Not in any of the test patterns, not in the games, not in the movies, anywhere on desktop, nor apps. And let me tell you that I have banding EVERYWHERE and ironically even in NVCPL itself.

 

Banding in the source again (everyone has it, e.g. on the PhysX page), like probably the case for your other cases too (yes, it's ~everywhere).
Some displays also make it even a lot worse.

 

Yeah, I figured as much. My theory is that it was always there, but once I started no notice it, I cannot unseen it.

 

Say, what is the probability of GPU causing the banding?

 

I think it's your display. Not all monitors (and especially HDTVs or monitor-TV combo devices) are capable of presenting smooth gradients (gray or any other color gradients for that matter) and it's often dependent on settings.
Most displays have decent gradients with correct settings which are usually the so called "neutral" or "no-op" settings where their processors do minimal work. But as soon as you touch anything except the backlight intensity (or on rare occasions even that one suffices) everything is thrown out of place quickly and heavily (banding and colorization occurs, often heavily even from the slightest adjustment of say the Contrast control but also from the R,G,B Gain controls which are actually per-channel contrast controls, etc).
So my advice is: reset the display and adjust the backlight intensity. Then try different presets. Standard may or may not work best but avoid things like Photo or Game mode (yes, game mode.... that's often less accurate than most and it's not always required to have lower latency since it's often just yet another color preset rather than an actual game mode with no special low-latency pipeline).

 

does the regedits still works?

 

1st post of this page (yes).

 

I have a aorus fi25f display. What panel do I have 8 or 10 bit. Because I can switch between 8 and 10 in nvcp.

 

8-bit panel

https://www.gigabyte.com/Monitor/AORUS-FI25F/sp#sp

https://www.displayspecifications.com/en/model/d7d820b2

 

When the display offers 10 bit, it most likely won't simply clip at 8 bit. Funny thing is that Nvidia enables dithering for 10 bit by default. Though most 10 bit displays are actually 8 bit + FRC, so you have dithering twice (so much for people who claim they could see dither patterns, this should basically dither their eyes out).

 

https://github.com/ledoge/novideo_srgb

This works.. the newest version added dithering option. you just need a calibrated icc profile to use with the program.make sure the ICC it's not in use by windows/installed in windows. copy the ICC to the novideo_srgb folder to be sure.

 

@ChaosDMNS will that program work on a laptop or it's made for standalone displays only?

 

It only works when the NV GPU renders the desktop and I assume the display also needs to be connected to it and not the IGP.

 

Wow - thanks! That tool is great. I can see obvious dithering when I select 6bit. Dithering is there with 8bit and 10bit too.

There is a known rendering tool, madVR, that has incredible dithering. It can perform 16bit dithering and then convert it back to whichever depth your panel has. Does NVidia dithering work the same way? Should I select 8bit dithering for 8bit (no FRC) VA panel or just the highest dithering level NoVideo-sRGB tool allows (10bit)?

 

I think you mean it does processing in 16bit (probably floating point format) and then converts to target bit depth with dithering.

When you don't use dithering, you can't keep precision in lower bit depth from color processing in higher bit depth and thus get banding. Generally dither to the same bit depth that is your display output. Temporal is more effective and should make dither patterns less noticeable (at least these are my findings with low dither/output depths), so try that first. madVR does temporal dithering by default too ("change dither patterns every frame").

Edit: I think precision is fine with novideo_srgb (or that driver API that it uses), I don't notice any additional banding introduced in test gradient with dithering. I also think Nvidia driver dithering is fine, I don't notice any dither grain either with temporal dithering 8 or 10 bit (1440p 27" 144Hz).

This btw. proves that dithering in the Nvidia Windows driver is fine, as there is no banding introduced after suspend etc. with novideo_srgb clamp + gamma correction active. It's just stupid Windows that ruins precision of GPU gamma ramps (when using Calibration Tools or DisplayCal VCGT loader, it's always bad when using the official Windows feature anyway).

 

nvidia internally handles at 12 or 13bits iirc.

 

I am surprise nobody has mentioned the following tool - https://github.com/ledoge/dwm_lut - that allows you to apply 3DLuts to your display for SDR and HDR. If you have calibrated you monitor and generated an ICC profile, you can use Displaycal to create a 3Dlut and use the tool in the link to load it in windows. You can follow the progress in the following link - I made a tool for applying 3D LUTs to the Windows desktop | DisplayCAL.