[Warner306]

It doesn't matter.  nVidia RGB is 8bit only.  Setting to 12bit doesn't survive a reboot anymore.  It always reverts to 8bit.  But, fwiw, FSW or FSE using 12bit RGB under 30Hz dithers to 10bit as it should, at least for 10bit sources like all HDR titles I've encountered.  SDR is all 8bit anyway.  Folks should understand even if you could retain the 12bit setting, not many displays can dither down to the 10bit that they are properly.  You would probably be doing more harm than good tbh.  If you happen to have a rare 12bit display, then it's different but only then.  This is why nfrickenvidia needs a 10bit RGB mode.

I don't agree. Before 10-bit UHD panels came along, virtually every 8-bit panel I've come across could dither a 12-bit input to 8-bits without banding. I have doubts it would be any different with 10-bits. The display should handle this in the exact same way, unless it is processing the image at a lower bit depth. Rounding from 10-bits rather than 12-bits before output could cause this problem. 12-bit support shouldn't be indicated by the display if this was the case. There is a reason why many high-end panels are still 8-bit FRC. Some of the new panel technology still isn't that great.

The causes of banding are bit (rounding) errors or displays that can't produce smooth gradients (lack of screen uniformity). Both could be issues with current panels. I'm guessing both of my 1080p displays handle internal image processing at 14-16 bits. Sony TVs process at 14-bits. Sony TVs shouldn't have any issue with a 12-bit input. The Vizio P Series Quantum are known to have significant issues with banding, and Vizio is supposed to be using true 10-bit panels. VA panel technology and/or 10-bit panels could be causing issues where lower bit depths are being used for image processing or gradients not being drawn smoothly.