madVR 10-bit Display Support Test

[James Freeman]

10-bit Display Support Test

This test will make it easier to see if your display actually supports 10bit input to output.
We already know that D3D11 + FSE in madVR will output a 10bit signal in windows 7 and up.
Now we just need to provide a super smooth black to white test pattern to clearly be able to see with our eyes.

First download 16bit PNG test patterns from here: http://www.bealecorner.org/red/test-patterns/Gradient-16bit.png
I also attached this PNG (zipped) at the bottom in case the URL disappears.
Open a new MPC-HC (or other player) window and drag the test pattern to the MPC-HC window.
Make sure RGB48 is enabled in LAV Video Decoder.

Adjust madVR settings as follows:
display->properties->10bit
display->calibration->disable & disable GPU gamma ramp.
rendering-> general-> Direct3D 11 ON
rendering->dithering->none
rendering->general->automatic exclusive fullscreen mode (FSE)-> off (for now).
Aero in Windows should be On.

When Dithering is Off the resulting output image will be a gradient in the bitdepth you set under properties.
You can switch between bit depths and dithering on/off to see what I mean, and then go back to 10bit dithering-off to continue the test.

Now go fullscreen without FSE (windowed fullscreen) to see the 8bit banding which should be visible because there are only 256 gradients from black to white.
This is because the GPU is still sending the image in 8bit to the display in this mode, even though we selected 10bit in madVR.
You may have to move closer to the display to actually see the gradients.

True 10bit output from your GPU needs FSE mode to work.
Now switch FSE On and go fullscreen again, now the GPU actually sends 10bit image to the display, and if your display supports 10bit input, you should now see 1024 gradients from black to white.
These gradients are 4 times narrower compared to 8bit and are practically indiscernible (to me).
In other words, you should NOT see any gradients.

If you still see the 8bit gradients even though the GPU sends 10bit to your display in FSE+D3D11 mode (check with Ctrl+J), your display does not support 10bit.

Important note for AMD users:

AMD cards dither the output by default, but you can disable it:


Check the Catalyst Control Center under "Information" -> "Software" to get the 2D driver path. Then run regedit.exe and open that path in the left pane.
You should see values in the right pane like "AdapterDesc" and a bunch of settings.
Add a DWORD value named TMDS_DisableDither (for DVI), DP_DisableDither (for DisplayPort), HDMI_DisableDither (for HDMI) with a value of 1. Reboot after.

Only that can explain why I see a difference between 8 and 10 bit output on my 6-bit DELL U2212HM connected with DVI


Note for NVIDIA users:

Since driver version 353.06 users can select bit depth in the Nvidia Control Panel on all systems.
If you can't see 10bit option in the CP, Nvidia will dither down to the bit depth selected if it is lower.

In other words, If you can't choose 10bit in nvidia CP and keep it on 8bit, when you run madVR in 10bit FSE, nvidia WILL Dither and you'll see smooth gradient, not true 10bit.
If you can select 10bit in Nvidia CP, the driver will NOT dither and sent true 10bit signal to your display.


Dell U2410 flickers and switches to 10bit mode and the image is smooth (first time seeing 10bit mode after owning this display for 5 years).

[luk008]

Disable GPU gamma ramp and disable dithering is only to proceed with test, right?

The requeriments to have 10 bit output are D3D11 + FSE + compatible GPU + compatible display?

[nevcairiel]

Unfortunately, the test isn't necessarily as reliable as one would hope. At least it may not tell you if your display can actually show 10-bit.

What happens for me, I tried this on both a screen known to have 10-bit support (also a U2410), as well as a screen I know which does not have 10-bit support - both connected over DP.
The result was that both screens showed a smooth gradient. Now I can only assume that the U2410 actually managed to show 10-bit, but what the other screen did, I'm not sure. Did it employ dithering? Does my GPU know that it doesn't take 10-bit, and does it dither? I don't know, and I don't know how to find out. :(

Obviously if you do see banding after the test, you do know that you should definitely stay away from 10-bit.

[tickled_pink]

The test seems to have worked for me. I noticed my TV flickered when it switched to 10-bit mode. Similar to how it flickers when switching between 50hz and 60hz. Could this be a tell tale sign that the TV in fact supports 10-bit?

[Asmodian]

No, it might flicker simply due to the GPU changing modes.

[huhn]

and don't forget nearly all TV support 10 or 12 bit input that doesn't tell us anything about the panel it self.
and using FSE with 10 bit doesn't mean 10 bit is outputted at all.

[MS-DOS]

To everyone:

AMD cards dither the output by default, but you can disable it:

http://www.monitortests.com/forum/Thread-Custom-Resolution-Utility-CRU?pid=3314#pid3314


Check the Catalyst Control Center under "Information" -> "Software" to get the 2D driver path. Then run regedit.exe and open that path in the left pane. You should see values in the right pane like "AdapterDesc" and a bunch of settings. Add a DWORD value named TMDS_DisableDither (for DVI) or DP_DisableDither (for DisplayPort) with a value of 1
HDMI_DisableDither for HDMI. Reboot after.

Only that can explain why I see a difference between 8 and 10 bit output on my 6-bit DELL U2212HM connected with DVI :)

[luk008]

To everyone:

AMD cards dither the output by default, but you can disable it:

http://www.monitortests.com/forum/Thread-Custom-Resolution-Utility-CRU?pid=3314#pid3314


HDMI_DisableDither for HDMI. Reboot after.

Only that can explain why I see a difference between 8 and 10 bit output on my 6-bit DELL U2212HM connected with DVI :)

Disabling AMD dithering I discovered that my TV is in fact 8 bits. I can see a smooth gradient with 10 bits when dithering is enabled. So should I still use 10 bits or just stay with 8?

[Zachs]

From memory when I tested this on over 10 monitors/TVs over half a year ago with MPDN, the link you use to your display makes a difference too (I.e. HDMI vs DVI vs analog). Some will even display corrupted image. Some works better when dx10 is used instead of dx11.

[MS-DOS]

Disabling AMD dithering I discovered that my TV is in fact 8 bits. I can see a smooth gradient with 10 bits when dithering is enabled. So should I still use 10 bits or just stay with 8?
I see no point in using 10 bit output in MadVR unless your monitor\TV supports 10 bit input. It will only decrease the overall image quality because of the need of two dithering steps, one by MadVR (16 -> 10) and another by the GPU (10 -> 8).

We disable dithering here just for test purposes. It should always be enabled when converting to a lower bit depth, otherwise you may see banding artifacts.

[baii]

I use a 16bit greyscale ramp png (converted from 10 bit test ramp.psd, which should be same as the 1 by AMD) that was made to test OPENGL 30bit support in photoshop.

It is much easier to spot if the panel do 10 bit.

https://mega.co.nz/#!OYoQ2IID!0CzRLlDL7v-RXxTjt4FPqDURwcEqWR70VyqpKROztK4

PS: enable LAV filter RGB48.

[tobindac]

This gives me dithering on 8bit for some reason. The other video you had showed 8bit more choppy. Unless the other one had a bug and didn't really show 8bit but less.

[tobindac]

Ah nevermind, your idea on madvr thread about the sharpening filter was actually good. On this file it makes it much easier to see the lines ('artifact removal').

This monitor is hilarious. I can see no artifacts on 10bit exclusive.

I guess the assumption is something dithers it, but is it for sure?

[bcec]

I use a 16bit greyscale ramp png (converted from 10 bit test ramp.psd, which should be same as the 1 by AMD) that was made to test OPENGL 30bit support in photoshop.

It is much easier to spot if the panel do 10 bit.

https://mega.co.nz/#!OYoQ2IID!0CzRLlDL7v-RXxTjt4FPqDURwcEqWR70VyqpKROztK4

PS: enable LAV filter RGB48.

Thanks for the file. What is the proper way to use it? This is what I did (please tell me if I did something wrong):
- Loaded the file up in mpc-hc x64
- Enabled Dx11 and FSE in madvr.
- Switched madvr to 10-bit
- Disabled refresh rate switcher.
- Switched mpc-hc to full screen.
- Disabled dithering.

I still see banding. The display itself should be 10-bit (or 8-bit+frc) afaik, so I was expecting not to see any banding.

[baii]

Thanks for the file. What is the proper way to use it? This is what I did (please tell me if I did something wrong):
- Loaded the file up in mpc-hc x64
- Enabled Dx11 and FSE in madvr.
- Switched madvr to 10-bit
- Disabled refresh rate switcher.
- Switched mpc-hc to full screen.
- Disabled dithering.

I still see banding. The display itself should be 10-bit (or 8-bit+frc) afaik, so I was expecting not to see any banding.

check crtl-J OSD, make sure it say RGB48LE, 16bit. If it is not, you need to check RGB48 in lav video decoder.

[bcec]

check crtl-J OSD, make sure it say RGB48LE, 16bit. If it is not, you need to check RGB48 in lav video decoder.

Thanks, that seems to be correct, it says RGB48LE, 16bit.

I noticed tho that madvr says: "full screen exclusive mode, new path" instead of "full screen exclusive mode, 10bit". Any ideas why?

[James Freeman]

All folks with AMD cards should redo the test with a small tweak noted in the first post.

MS-DOS pointed out that AND driver dithers the output when it outputs more than 8bit, so you may actually get dithered 8bit which looks like 10bit on ANY panel.
Nevciriel pointed that he gets a smooth ramp even with a known not 10bit panel, and MS-DOS pointed that his 6-bit DELL U2212HM is also smooth...
So all you AMD folks need to do a little registry work to test actual 10bit output and not dithered 8bit by AMD driver.

[bcec]

Thanks, that seems to be correct, it says RGB48LE, 16bit.

I noticed tho that madvr says: "full screen exclusive mode, new path" instead of "full screen exclusive mode, 10bit". Any ideas why?

aero was off. When on, it worked, thanks!

[James Freeman]

I use a 16bit greyscale ramp png (converted from 10 bit test ramp.psd, which should be same as the 1 by AMD) that was made to test OPENGL 30bit support in photoshop.

It is much easier to spot if the panel do 10 bit.

https://mega.co.nz/#!OYoQ2IID!0CzRLlDL7v-RXxTjt4FPqDURwcEqWR70VyqpKROztK4

PS: enable LAV filter RGB48.

Great Thanks.
Much easier to see and works with x64 indeed.

I also found 16bit PNG that is much smaller so I should edit my first post with it.

[huhn]

just to add my experiences.

i use a cheap Phillips TV it supports 12 bit input and is not chroma subsampling at all. the panel is clearly an 8 bit ips panel.

test picture set to video frame double size to see more banding.

FSE D3D11 10 bit
AMD set to 8 bit output no dither = clear high banding
AMD set to 10 bit output no dither= little banding
AMD set to 12 bit output no dither=little banding

8 bit window mode
no dither clear high banding
madVR dither=little banding

these dither "hacks" are set in the registry. without these hacks AMD set to 8 bit was still pretty good so the GPU can dither on is own with at least ok quality. but i will double check that later.

looks like my screen can use proper dithering

[potomac]

i saw difference from 8 to 10 bit (LG IPS235) because of amd dither :)

[James Freeman]

i saw difference from 8 to 10 bit (LG IPS235) because of amd dither :)

That's good to know.
To properly test the panel one should disable software/driver dithering completely.
AMD does dithering without the user knowledge or ability to control it in a user friendly way... pity.

[ryrynz]

I take it back.. it would help if I let the player go into FSE mode...

I can clearly see a difference with 10 bit output even on my 6 bit + FRC panel. There's definitely a benefit to enabling it even on my ~1000:1 U2412.
I can see a small difference between using 8 bit and 10 bit with dithering enabled, IMO 8 bit with dithering is superior to 10 bit with no dithering.. it's kinda close though.
I'd say it's likely most would stand to benefit from having it enabled.

[James Freeman]

ryrynz are you using AMD card?
If you are using Nvidia then the U2412 actually dithers the 10bit input to its native 6bit which is good!
If you are on AMD please refer to the first post and disable driver dithering via registry hack.

[ryrynz]

nah it's Intel HD4000, I'm testing out the plasma now.. have also found a madVR bug.

[potomac]

That's good to know.
To properly test the panel one should disable software/driver dithering completely.
AMD does dithering without the user knowledge or ability to control it in a user friendly way... pity.

it's better or not to enable amd dithering?

[Morku]

I have an HP ZR24w which should be 8-bit panel.
I made the test. If I understand right, I shouldn't notice any difference, right? But in my case, I see a difference. In window mode I can clearly see the vertikal lines. Also in windowed fullscreen, in FSE they disappear.
So I want to know... is that correctly?
I my logical thinking, I would stay at 10-bit, because it improves the gradient.

I have NVIDIA GTX480, No AMD...

[ryrynz]

I made the test. If I understand right, I shouldn't notice any difference, right?

Based on various user's experience that would not be right. Even 6 bit panels benefit from having 10 bit enabled, but the difference is of course easily visible when dithering is disabled.
When it's enabled it's a lot harder to see the benefit with (as James has pointed out) sub 1000:1 displays, but of course if you can see a benefit with dithering disabled then it's certainly there with dithering enabled.. So yes enable it if that's the case!


I my logical thinking, I would stay at 10-bit, because it improves the gradient.


Exactly.

[tyto]

Prolite B2475HDS clearly supports 10bit for who may be interested

[Morku]

@ryrynz
Thanks for pointing out :)

Just one more question. Should I left dithering option disabled for FSE? Or enable again (for the slightly improved placebo image quality)?
Or depends on the source material?

Of course, this question is just for FSE option relevant, because dithering enabled improves image quality for windowed mode.

[nevcairiel]

You should always enable dithering.

[James Freeman]

You should always enable dithering.

To add to that;

Dithering should always be in the last step, and preferable the better quality dithering should be used.
Also preferably, only one dithering stage should be applied for less noise.

If the display dithers 10bit input to its 6bit or 8bit panel (6/8+FRC) and madVR also dithers, you'll have two dithering stages with "noisier" image.

If the panel is 6bit it would be better to send 6bit and dithering from madVR.
If the panel is 8bit it would be better to send 8bit and dithering from madVR.
If the panel is 8bit+FRC (accepts 10bit input) it still would be better to send 8bit and dithering from madVR because madVR dithering is better quality than the mystery FRC inside the monitor.
If the panel is a true 10bit (like Dell U3014) it would be better to send 10bit and dithering from madVR for optimum performace.

To summarize;
It is better to use madVR 6bit + Dithering unless your panel is true 8bit.
It is better to use madVR 8bit + Dithering unless your panel is true 10bit.
If your panel is true 10bit (not 8+FRC) use 10bit + Dithering in madVR.

This is true for computer monitors with known native panel bit depth, TVs are a different story.

A lot of users will want to realize their display capability of 10bit, but the real question is whether it is worth the extra dithering from the display itself if it is not a true 10bit panel....

[ryrynz]

If the panel is 6bit it would be better to send 6bit and dithering from madVR.

Better? Selecting 6 bit + ED2 dithering (on my 6 bit panel) shows more grain through the whole smallramp picture, I don't see any ramps though, switching to 8+ bit does provide a much smoother picture however, which is "better" isn't it?

[huhn]

That's good to know.
To properly test the panel one should disable software/driver dithering completely.
AMD does dithering without the user knowledge or ability to control it in a user friendly way... pity.

you have full control of the output bit deep and AMD is just dithering to that bit deep you selected what do you want more.

it's simply the correct way to do things.

[James Freeman]

ryrynz,
Try ordered dithering with change every frame but turn off colored noise, this is more or less what FRC does according to Wikipedia.
BUT, make sure you use the Grey Ramp test pattern from "madTestPatternSource" (smallramp.ytp) because with a static image the dithering pattern will not "change every frame" because there is none.


you have full control of the output bit deep and AMD is just dithering to that bit deep you selected what do you want more.
it's simply the correct way to do things.

You are right, I sometimes use the nvidia control panel Contrast, Brightness, Gamma, Color controls to lower my display brightness (its already on "0" in the display),
I would love to have dithering after that by the driver like AMD does because I see terrible banding on a grey scale.
Nvidia does its color adjustment processing in control panel in 8bit without dithering.

But I also would not want to apply two or three dithering stages without knowing.
MadVR dithering + AMD dithering + 8bit+FRC display = 3 stage dithering which can be easily turned on unknowingly.

[MS-DOS]

AMD set to 8 bit output no dither = clear high banding
AMD set to 10 bit output no dither= little banding
AMD set to 12 bit output no dither=little banding

When you change output bit depth in CCC, does your screen fade black like it does when switching refresh rates?

I have an HP ZR24w which should be 8-bit panel.
I my logical thinking, I would stay at 10-bit, because it improves the gradient.

Yes it has a 8 bit panel, but without FRC. So, no, in your case it doesn't.


If the panel is 6bit it would be better to send 6bit and dithering from madVR.
If the panel is 8bit it would be better to send 8bit and dithering from madVR.
If the panel is 8bit+FRC (accepts 10bit input) it still would be better to send 8bit and dithering from madVR because madVR dithering is better quality than the mystery FRC inside the monitor.
If the panel is a true 10bit (like Dell U3014) it would be better to send 10bit and dithering from madVR for optimum performace.

To summarize;
It is better to use madVR 6bit + Dithering unless your panel is true 8bit.
It is better to use madVR 8bit + Dithering unless your panel is true 10bit.
If your panel is true 10bit (not 8+FRC) use 10bit + Dithering in madVR.

I'm not so sure about 6\8 bit + FRC, though. Advanced framerate control works different from normal dithering

Dithering and Frame Rate Control (FRC) relate to the colour depth of a monitor panel and are technologies used to boost the colours which the matrix can display. For instance TN Film screens are traditionally more economical than other technologies when it comes to colour depth. In fact, they only display 64 red, 64 blue and 64 true green shades by default through pixel rotations. The maximum amount of colours achievable from liquid crystal rotation alone is 262,144. In order to reach 16 million colours and above, panel manufacturers commonly use two technologies: Dithering and Frame Rate Control (FRC). These terms are often interchanged, but strictly can mean different things.



Spatial Dithering - This dithering method involves assigning appropriate colour values from the available colour palette to close-by pixels in such a way that it gives the impression of a new colour tone which otherwise could not have been created at all. In doing so, there complex mappings according to which the ground colours are mutually assigned, otherwise it could result in colour noise / dithering noise. Dithering can be used to allow 6-Bit panels, like TN Film, to show 16.2 million perceived colours. This can however sometimes be detectable to the user, and can result in chessboard like patterns being visible in some cases. Spatial dithering is rarely used in the modern market and instead Frame Rate Control is more widely utilised.


Frame Rate Control / Temporal Dithering - The other method is Frame-Rate-Control (FRC), also referred to sometimes as temporal dithering. This works by combining four colour frames as a sequence in time, resulting in perceived mixture. In basic terms, it involves flashing between two colour tones rapidly to give the impression of a third tone, not normally available in the palette. This allows a total of 16.2 reproducible million colours in 6-bit TN Film matrices. FRC is also used to enhance the colour depth of 8-bit panels, boosting them from their standard 16.7 million colours to 1.07 billion in the case of "10-bit" panels (8-bit + FRC). There are a number of FRC algorithms which vary in their effectiveness. Sometimes, a twinkling artefact can be seen, particularly in darker shades, which is a side affect of such technologies.

My U2212HM is 6 bit + FRC and outputting 6 bit with MadVR only adds more noise comparing to 8.

[noee]

....
But I also would not want to apply two or three dithering stages without knowing.
MadVR dithering + AMD dithering + 8bit+FRC display = 3 stage dithering which can be easily turned on unknowingly.

That's exactly what I'm doing. My secondary monitor is only used for VIdeo and is 8bit-FRC, so I disable the AMD dither and set madVR to 10bit and go from there.

[huhn]

When you change output bit depth in CCC, does your screen fade black like it does when switching refresh rates?

yes it does.

and going to FSE 10 bit mode take a very long time.

[ryrynz]

ryrynz,
Try ordered dithering with change every frame but turn off colored noise, this is more or less what FRC does according to Wikipedia.
BUT, make sure you use the Grey Ramp test pattern from "madTestPatternSource" (smallramp.ytp) because with a static image the dithering pattern will not "change every frame" because there is none.


Tried it, though I am face up within two feet of the screen with the lights turned off but I can quite easily see the patches of dither areas in 6 bit with OD (with CN disabled and CEF enabled as you mentioned)
So your assumptions don't really hold true here.


and going to FSE 10 bit mode take a very long time.

It takes some time for sure.


Yes it has a 8 bit panel, but without FRC. So, no, in your case it doesn't.


I would rather him say if it did or not to be sure, it looks like actual results seem to fly in the face of theory.


My U2212HM is 6 bit + FRC and outputting 6 bit with MadVR only adds more noise comparing to 8.

Same here.

[feelingblue]

Excuse me, but in the driver panel we must flag 10bit or not?

With EDID my video driver automatically sets YCbCr444 10bit
i think that this maybe a way to understand if the panel support 10bit

there is a way to read edid info?

a similar tool is reliable?
http://developer.amd.com/tools-and-sdks/graphics-development/amd-edid-utility/

[huhn]

Excuse me, but in the driver panel we must flag 10bit or not?

With EDID my video driver automatically sets YCbCr444 10bit
i think that this maybe a way to understand if the panel support 10bit

there is a way to read edid info?
the EDID doesn't tell you at all if your panel is 10 bit you only learn if your Tv support high bit deep input that's all and nearly all support 12 bit input.

AMD uses by default 10 bit if possible and YCbCr. if you select 8 bit in the AMD driver it will only output 8 bit so yes it should be at 10 bit.

first you should check if your Tv supports unlimted RGB than you have to do some test if your TV can dither 10 bit input or display it.

if you don't fully understand how this works you should simply stick with dithered 8 bit madVR.

i'm just guessing you are using AMD because nvidia and intel doesn't have such option in there driver yet.

[feelingblue]

Thanks

I have not a TV but a VPR.
The functioning is different compared to a TV, there is not a fisical panel.
the manufacturer declares support for 10bit, but if as you said ATI driver and EDID are not affidable the only way is to do comparison test.

My VPR yes, support unlimited RGB.

[RenderGuy2]

It would interesting to test and confirm that a 10bit signal can pass from MadVR/MPDN through the video card without being dithered/altered along the way.

The only way I can think of to test this would be to use an HDMI capture card. The more expensive ones can capture/record uncompressed 10bit RGB. Even some of the less expensive cards can capture 4:2:0 10bit YUV. One could play some 10bit patterns out to the capture card. By analyzing the captured footage, it should be easy to determine if dithering occurred along the way.


Anyone own a capture card capable of 10bit recording?

Unfortunately I do not.

[huhn]

It would interesting to test and confirm that a 10bit signal can pass from MadVR/MPDN through the video card without being dithered/altered along the way.

The only way I can think of to test this would be to use an HDMI capture card. The more expensive ones can capture/record uncompressed 10bit RGB. Even some of the less expensive cards can capture 4:2:0 10bit YUV. One could play some 10bit patterns out to the capture card. By analyzing the captured footage, it should be easy to determine if dithering occurred along the way.


Anyone own a capture card capable of 10bit recording?

Unfortunately I do not.

we don't even know if a 8 bit picture isn't altered.

[noee]

the EDID doesn't tell you at all if your panel is 10 bit you only learn if your Tv support high bit deep input that's all and nearly all support 12 bit input.

AMD uses by default 10 bit if possible and YCbCr. if you select 8 bit in the AMD driver it will only output 8 bit so yes it should be at 10 bit.

first you should check if your Tv supports unlimted RGB than you have to do some test if your TV can dither 10 bit input or display it.

if you don't fully understand how this works you should simply stick with dithered 8 bit madVR.

i'm just guessing you are using AMD because nvidia and intel doesn't have such option in there driver yet.

Do you know if this is true with the 13.12 driver that does not actually have the bit depth option?

I ask because I cannot see a difference in the test pattern when sending 10bit from madVR with the AMD HDMI_DisableDither either on or off, so it appears that it just sends the 10bit signal on to the monitor without futzing with it.

[huhn]

Do you know if this is true with the 13.12 driver that does not actually have the bit depth option?

it doesn't have this option.

i guess AMD is just outputting 10 bit in this case if possible it just a black box on this driver.

[James Freeman]

FRC works by combining four colour frames as a sequence in time, resulting in perceived mixture. In basic terms, it involves flashing between two colour tones rapidly to give the impression of a third tone, not normally available in the palette.

The question is how fast?
MadVR dithering is limited to the display refresh rate (or eve slower, the movie frame rate?).
Do you think FRC is faster than the display refresh rate? If so, it has an advantage over madVR in lower bit depths where you can still see the pattern.
The faster the change the smoother and less noticeable the pattern is.

[baii]

It boils down to the lack of real test pattern/tools for this sort of thing, it is not hard to tell if a panel do 8 or 10bit,
but to compare 8bit dither vs native 10bit vs 10bit dither? Probably need 3+ monitor attached to GPUs ~ and the only one that can make judgement is human eye~~

8bit dither -> any bitdepth panel-> smooth gradient
10bit native -> 8 bit or lower panel-> banding
10bit native -> 10bit/8bit+frc panel -> smooth gradient
10bit dither -> any bitdepth panel -> smooth gradient

I guess one can take picture then try to get the SNR, would be a nice scientific project ~

[RenderGuy2]

we don't even know if a 8 bit picture isn't altered.

True, this would be interesting to test as well. Though it should be easy to determine if 10 bit data was ever reduced to 8 bits. For example, if you sent a 10 bit gradient out to the capture card and then viewed a histogram of the captured gradient, I imagine you would see evenly spaced gaps/peaks in the histogram if it was reduced to 8 bits along the way. Anyway, if nobody has a capture card, I guess we'll never know.

[MS-DOS]

yes it does.

and going to FSE 10 bit mode take a very long time.
A few more questions if you don't mind: What's your monitor? Is it connected with DisplayPort or HDMI? Does the color format setting in CCC stay at RGB when you switch the output bit depth there to 10 bit?

The question is how fast?
I couldn't find any information regarding this. Let's just say, for me it's good\fast enough to prefer it over an additional portion of normal dithering :)