who can use Linux but not windows? Share your Linux setup

WhisperingWind

If the static image on your monitor is truly static without any movement, then there is no temporal dithering. I think this would be visible on your monitor's slow matrix, though I'm not a specialist in such screens.

To detect spatial dithering, for example a checkerboard pattern, you would need to see each individual pixel - this is impossible with the naked eye and difficult with a standard phone camera. Although perhaps a microscope and a phone could help with that. But this pattern still needs to be found and identified, which can also be difficult.

Linux

I advise you to install UMR and figure out how to disable spatial dithering. Then go by how it feels.

Windows 10

As an option, install Windows 10 22H2. The ColorControl application completely disables dithering on my RX6600. But here people were complaining about update KB5075912: it was released on February 10, 2026. Find an older version of Windows 10 without this update and don't update. For me, Windows 10 with updates up to October 2015 works. Together with an RX6600, it's a delight for the eyes. Since you also have AMD GPU, maybe it will work for you too.

gety9

WhisperingWind

I advise you to install UMR and figure out how to disable spatial dithering.

installed umr, found FMT_BIT_DEPTH_CONTROL

minipc:umr$ 
sudo umr --list-blocks | grep -i dcn
        green_sardine.dcn210 (2.1.0)

minipc:umr$ 
sudo umr -r "*.dcn210.mmFMT*" 2>/dev/null | head -20
dcn210.mmFMON_CTRL => 0x0001f040
dcn210.mmFMT0_FMT_422_CONTROL => 0x00000000
dcn210.mmFMT0_FMT_BIT_DEPTH_CONTROL => 0x00008900
dcn210.mmFMT0_FMT_CLAMP_CNTL => 0x00000001
dcn210.mmFMT0_FMT_CLAMP_COMPONENT_B => 0x00000000
dcn210.mmFMT0_FMT_CLAMP_COMPONENT_G => 0x00000000
dcn210.mmFMT0_FMT_CLAMP_COMPONENT_R => 0x00000000
dcn210.mmFMT0_FMT_CONTROL => 0x00000000
dcn210.mmFMT0_FMT_DITHER_RAND_B_SEED => 0x00000000
dcn210.mmFMT0_FMT_DITHER_RAND_G_SEED => 0x00000000
dcn210.mmFMT0_FMT_DITHER_RAND_R_SEED => 0x00000000
dcn210.mmFMT0_FMT_DYNAMIC_EXP_CNTL => 0x00000011
dcn210.mmFMT0_FMT_MAP420_MEMORY_CONTROL => 0x00003300
dcn210.mmFMT0_FMT_SIDE_BY_SIDE_STEREO_CONTROL => 0x00000000
dcn210.mmFMT1_FMT_422_CONTROL => 0x00000000
dcn210.mmFMT1_FMT_BIT_DEPTH_CONTROL => 0x00600000
dcn210.mmFMT1_FMT_CLAMP_CNTL => 0x00000000
dcn210.mmFMT1_FMT_CLAMP_COMPONENT_B => 0x00000000
dcn210.mmFMT1_FMT_CLAMP_COMPONENT_G => 0x00000000
dcn210.mmFMT1_FMT_CLAMP_COMPONENT_R => 0x00000000

currently i have

minipc:umr$ 
sudo umr -O bits -r "*.dcn210.mmFMT0_FMT_BIT_DEPTH_CONTROL"
dcn210.mmFMT0_FMT_BIT_DEPTH_CONTROL => 0x00008900
        .FMT_TRUNCATE_EN[0:0]                                            ==        0 (0x00000000)
        .FMT_TRUNCATE_MODE[1:1]                                          ==        0 (0x00000000)
        .FMT_TRUNCATE_DEPTH[4:5]                                         ==        0 (0x00000000)
        .FMT_SPATIAL_DITHER_EN[8:8]                                      ==        1 (0x00000001)
        .FMT_SPATIAL_DITHER_MODE[9:10]                                   ==        0 (0x00000000)
        .FMT_SPATIAL_DITHER_DEPTH[11:12]                                 ==        1 (0x00000001)
        .FMT_FRAME_RANDOM_ENABLE[13:13]                                  ==        0 (0x00000000)
        .FMT_RGB_RANDOM_ENABLE[14:14]                                    ==        0 (0x00000000)
        .FMT_HIGHPASS_RANDOM_ENABLE[15:15]                               ==        1 (0x00000001)
        .FMT_TEMPORAL_DITHER_EN[16:16]                                   ==        0 (0x00000000)
        .FMT_TEMPORAL_DITHER_DEPTH[17:18]                                ==        0 (0x00000000)
        .FMT_TEMPORAL_DITHER_OFFSET[21:22]                               ==        0 (0x00000000)
        .FMT_TEMPORAL_LEVEL[24:24]                                       ==        0 (0x00000000)
        .FMT_TEMPORAL_DITHER_RESET[25:25]                                ==        0 (0x00000000)
        .FMT_25FRC_SEL[26:27]                                            ==        0 (0x00000000)
        .FMT_50FRC_SEL[28:29]                                            ==        0 (0x00000000)
        .FMT_75FRC_SEL[30:31]                                            ==        0 (0x00000000)

Do i understand it right that i need to disable 3: FMT_SPATIAL_DITHER_EN, FMT_SPATIAL_DITHER_DEPTH and FMT_HIGHPASS_RANDOM_ENABLE?

markdotpeters5

gety9 Just use Mint XFCE edition, turn off the compositor and turn on 'full composition pipeline' on the card in Nvidia settings. Boom, no dithering. (assuming Nvidia of course!)

WhisperingWind

gety9

In theory, you only need to disable FMT_SPATIAL_DITHER_EN - the other bits just control the finer details of spatial dithering. Once dithering is turned off, they don't matter anyway.
But if you want to do everything thoroughly and avoid surprises, you can clear them all (FMT_SPATIAL_DITHER_EN, FMT_SPATIAL_DITHER_DEPTH, and FMT_HIGHPASS_RANDOM_ENABLE).

gety9

WhisperingWind

Registry writes applied instantly? sudo umr -w "*.dcn210.mmFMT0_FMT_BIT_DEPTH_CONTROL" 0x00000000 and visually results should be seen (if command is helpful)?

Not only. Dithering can occur even if the monitor is true 8-bit and 8-bit is set in the GPU settings. This dithering will not add colors (since we did not explicitly request it), but it will smooth out gradients.

gradient is exactly what i am trying to understand now.

As test i send pixel data in 4 bands (LUT bands). So regular gradient is divided in 4 stripes. It works and bands have equal size, but area where 2 bands touch area is smoothed and not only that there are stripes darker (not beloning to 2 close bands).

It's same for both monitors, and Dasung and NEC LCD. So i was sure that it's gpu spatial dithering, but above command didn't help.

Both monitors display perfect evenly cut (with no smooth areas) if it's not gradient but hard coded color

So i assumed my 4 bands trick should achieve the same?

WhisperingWind

gety9

This could be dithering from the display itself, or alternatively, the GPU-side dithering may not be fully disabled.

You could try Windows 10 as I mentioned above and see how it feels.

On my RX 6600, spatial dithering looks like random static noise mixed into the image, so it does not strain the eyes. The red marks indicate pixels that differ between the default spatial dithering mode and dithering disabled. Although your spatial dithering pattern may be different, I don't think your eyes hurt because of spatial dithering.

Registry writes applied instantly? sudo umr -w "*.dcn210.mmFMT0_FMT_BIT_DEPTH_CONTROL" 0x00000000 and visually results should be seen (if command is helpful)?

Yes, instantly.

Both monitors display perfect evenly cut (with no smooth areas) if it's not gradient but hard coded color

In this test, we are most interested in gradient transitions, as that's where banding can be observed.

jordan

gety9 here's a tool I made that lets you mess with the controls easier. I can't remember which version this is, might be a older one. It's been awhile since I worked on it but should work just fine. It's basically just a gui for UMR

https://drive.proton.me/urls/KKC47JA9XW#GKfEkzZWgdXC

There's a register that randomizes the spatial dither too. Also if you use the tool don't enable frame random as it'll make flicker bad.

Sygey

@"WhisperingWind"

Please tell me what the configuration of your rx6600 computer is. Processor, motherboard, RAM, power supply, and monitor. Do you use xmp? What operating system are you currently using, and are updates enabled? What is the driver on your graphics card? Is the chipset driver installed?

Thx!

WhisperingWind

Sygey

Please tell me what the configuration of your rx6600 computer is. Processor, motherboard, RAM, power supply, and monitor. Do you use xmp?

GPU: Sapphire AMD Radeon RX 6600 PULSE.

Motherboard: Z390 AORUS MASTER G2 Edition (rev. 1.0); BIOS F20 (2013); Resizable BAR enabled; Compatibility Support Module disabled.

RAM: Kingston Fury 3200MHz 32GB DDR4 RAM (4x8GB). XMP profile applied: 3200MHz.

CPU: i9-9900K without overclocking (Intel UHD630 iGPU is disabled).

Power supply: BeQuiet SYSTEM POWER 9 700W.

Monitor: Sony KD-49XG8096 TV.

This is for movies, games, and browsing when I don't feel like getting out of your chair; used only with the TV.

What operating system are you currently using, and are updates enabled?

Windows 10 22H2. Updates as of October 2015; update capability disabled via Windows Update Blocker.

What is the driver on your graphics card?

I don't remember the exact version, but it's from 2015, around May I think (I don't have a way to check right now). Spatial dithering is disabled via ColorControl (it is the only one enabled by default).

Is the chipset driver installed?

I didn't install any drivers except for the GPU on purpose; I think Windows 10 might have installed them by itself.

Sygey

@"WhisperingWind"

Can you take a screenshot of the settings in the Color control program? Thank you!

WhisperingWind

Sygey

Sorry, I can't right now. I won't be home for another couple of months - I'm on a business trip.

I only have the Dithering option set to 'included'. The value is 'Disabled'.

macsforme

macsforme I plan to mess with recompiling the kernel after I can set up the base operating system in a more permanent setup versus using a live USB or temporary installation partition. I'm very curious if this 2015 Retina MacBook Pro display can be made stable/comfortable under any conditions.

I finally set up Ubuntu on my 2015 15-inch Retina MacBook Pro with @WhisperingWind's patched kernel to disable dithering when xrandr is used to set 6-bit color. To work around some strange compiler errors (possible I/O problems on the internal SSD controller?), I had to compile the kernel in a live USB environment. The evidence certainly indicates that it is working, based on clear banding on the login screen and a gradient test image appearing no smoother above 6-bit:

I have not used it casually enough to report a subjective difference. However, one of the noteworthy characteristics of the display was speckling in my peripheral vision when displaying certain images (for example the macOS High Sierra default wallpaper), and this effect does not appear to be reduced when running at 6-bit with this patched kernel. There is also a sensation of subtle movement in the image, at least as bad or possibly worse than at 8-bit. I played around with displaying the image in a barebones X environment (via startx), and while I am not 100% confident the experiment was valid, there was no improvement.

I suspect there must be some factor causing strain on this machine other than temporal dithering, or else something is compensating for the lower bit depth and introducing another issue. If anyone has other ideas to try while on this custom kernel setup, I am eager to hear them and give them a shot. Otherwise, it appears that reducing the bit depth did not make this panel comfortable for me.

Sunspark

Turn down the brightness. Try 50%.

Donux

Based on my latest experience, if you get UHD620 laptop, with glossy WQHD non flicker screen, and install LATEST! ubuntu, you will be in alice wonderland. You are really only gambling on PWM here, since all these old UHD620 will be probably good with backlight tech, polarisation etc.

markdotpeters5

Donux I was going to say that it won't let you turn off compositor, but I've just tried it and actually seems very comfortable. Might switch to this from Mint XFCE of it continues to hold up.

K-Moss

Donux UHD 620 is better than 700 versions? How/why?

Donux

markdotpeters5 I did not tinker with OS at all, and will not on autopilot ever do this. The best setup is default, if there is no apprent problem. Any modification is a potential risk, especially to linux system, as it break other things as you try to do it. And I am doing this on lenovo X1 yoga gen 3 which has 1415Hz PWM or something close to this value. It feels very usable. Of course I wish I had PWM free panel too.

markdotpeters5

Donux I got problems after a few minutes and had to stop using it. At least for my hardware setup it doesn't seem to work for me.

Donux

markdotpeters5 Sorry to hear this. I been there too with other machines. It seams like whatever you install it just makes strain even worse. Intel Xe is an absolute worst nightmare if you have one.

markdotpeters5

Donux Gunna stick with Mint XFCE, turning compositor off makes it the most comfortable OS I've used on any hardware I've tried it on

K-Moss

Donux Which generations of Intel CPU integrated graphics have you found best?

K-Moss

markdotpeters5 Doubtful that is any better than Kubuntu where you set output to 8 bits in display settings.

romtelekom

I think should buy a cheap Carson Microflip microscope to check for dithering, that way you can make sure if it had any effect.

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