Is 10-bit color mode presentation supported on current OS desktop compositors? I was aware that, at least on Windows, it is not and dirty OGL "hacks" are needed .__.

It is recommended practice on Windows to use 10bit backbuffers!

I have a BenQ BL3201PT 32" UHD display that supports 10bit color channels on Windows desktop ... the 10bpc mode is implemented with FRC (frame rate control) [AKA 8bit with dithering]
...I don't see any difference in anything with 10bpc vs 8bpc, i.e. 8bpc does not produce banding

Bold bit is the problem
8bpc does produce very perceptible banding in contrived conditions. Try opening photoshop and making a linear gradient from black to 100% green, then zoom in on a dark section of it -- e.g. the individual bands of green should be easily distinguisable.

Real 10bit, or even fake (dithered) 10bit-via-8bit should relieve this somewhat. So even with the existing sRGB color space 10bit is a good improvement over 8bit.

If you go to a wider gamut, such as Rec.2020, then you also have to add more bits (than 8), otherwise you'll end up with less precision than existing 8bit sRGB. In the end, you don't get that much extra precision (but you do get a better gamut)! 10bit sRGB or 12bit Rec.2020 would be ideal

[edit] the intense white surrounding that dark image ruins your eye's perception of it. Hold your hands up to frame the dark green section (and block out that white light), and you should be able to make out an obvious diagonal line (or two!) in the middle, separating the different shades of green.

Looking forward to seeing a display first hand that would support the full Rec.2020 space. Anyone knows if such displays are actually available for purchase yet?

As far as I know current tech is only able to display 97% of the DCI colorspace (which only cover a part of REC 2020's one). Manufactors say that next generation of quantum dot/ led should make possible to reach 90% of rec 2020 colorspace.

Hopefully this new monitors will be better calibrated than srgb ones because I'm expecting them to be much more difficult to calibrate. Plus there is still no dedicated way to make d3d or Ogl use icc profiles...

Is 10-bit color mode presentation supported on current OS desktop compositors? I was aware that, at least on Windows, it is not and dirty OGL "hacks" are needed .__.

It is recommended practice on Windows to use 10bit backbuffers!

I have a BenQ BL3201PT 32" UHD display that supports 10bit color channels on Windows desktop ... the 10bpc mode is implemented with FRC (frame rate control) [AKA 8bit with dithering]
...I don't see any difference in anything with 10bpc vs 8bpc, i.e. 8bpc does not produce banding

Bold bit is the problem
8bpc does produce very perceptible banding in contrived conditions. Try opening photoshop and making a linear gradient from black to 100% green, then zoom in on a dark section of it -- e.g. the individual bands of green should be easily distinguisable.

Real 10bit, or even fake (dithered) 10bit-via-8bit should relieve this somewhat. So even with the existing sRGB color space 10bit is a good improvement over 8bit.

If you go to a wider gamut, such as Rec.2020, then you also have to add more bits (than 8), otherwise you'll end up with less precision than existing 8bit sRGB. In the end, you don't get that much extra precision (but you do get a better gamut)! 10bit sRGB or 12bit Rec.2020 would be ideal

[edit] the intense white surrounding that dark image ruins your eye's perception of it. Hold your hands up to frame the dark green section (and block out that white light), and you should be able to make out an obvious diagonal line (or two!) in the middle, separating the different shades of green.

Yes, the 10-bit back-buffer is not an issue, but what DXGI format use the DWM? I was aware that it still a 8-bit color buffer.

Looking forward to seeing a display first hand that would support the full Rec.2020 space. Anyone knows if such displays are actually available for purchase yet?

Manufactors say that next generation of quantum dot/ led should make possible to reach 90% of rec 2020 colorspace.

Unfortunately that will probably take a while to filter down to South Africa (for broad usage).

But progress is nice, Maybe I will be able to skip straight from my standard/normal/RunOfTheMill monitor to something like this :)

10 10 10 2 ? so only 2 (01 and 10) transparency levels, beside opaque (11) and transparent (00) ?? so, no fog effect...