Well i think every manufacterer is saying true 8bit screen, but the monitor may have a weakness at some level with e.g. gray and dithers is always on as a choice of the manufacterer. True 8bit could be just "nearly true" 8-bit.

caboy There is more advanced option to get the display information by parsing the EDID blob. Below is my display.

00 ff ff ff ff ff ff 00 06 10 3e a0 00 00 00 00

10 1b 01 04 b5 1d 12 78 02 0f 81 ae 52 43 b0 26

0d 50 54 00 00 00 01 01 01 01 01 01 01 01 01 01

01 01 01 01 01 01 d9 65 00 50 a0 40 2e 60 08 20

08 08 1e b3 10 00 00 1a 00 00 00 fc 00 43 6f 6c

6f 72 20 4c 43 44 0a 20 20 20 00 00 00 10 00 00

00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 10

00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 72

70 12 79 03 00 7f 81 3f fa 10 00 03 01 18 0f 28

17 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

4c 50 31 33 33 57 51 35 2d 53 4a 41 37 0a 20 00

44 43 4e 31 33 30 32 30 30 32 58 50 58 47 54 41

4b 0a 20 20 20 20 20 7f 81 29 fa 10 00 02 01 00

11 00 00 02 90 03 65 04 89 06 18 08 38 0b 20 0f

19 14 8a 1c 00 26 3d 34 51 47 ae 62 5a 87 21 b9

e3 ff 7d 00 00 00 00 00 00 00 00 00 00 00 b3 90

----------------

Block 0, Base EDID:

  EDID Structure Version & Revision: 1.4

  Vendor & Product Identification:

    Manufacturer: APP

    Model: 41022

    Made in: week 16 of 2017

  Basic Display Parameters & Features:

    Digital display

    Bits per primary color channel: 10

    DisplayPort interface

    Maximum image size: 29 cm x 18 cm

    Gamma: 2.20

    Supported color formats: RGB 4:4:4

    First detailed timing includes the native pixel format and preferred refresh rate

  Color Characteristics:

    Red  : 0.6796, 0.3203

    Green: 0.2646, 0.6904

    Blue : 0.1503, 0.0507

    White: 0.3125, 0.3291

  Established Timings I & II: none

  Standard Timings: none

  Detailed Timing Descriptors:

    DTD 1:  2560x1600   60.000828 Hz   8:5     98.761 kHz    260.730000 MHz (286 mm x 179 mm)

                 Hfront    8 Hsync  32 Hback   40 Hpol P

                 Vfront   32 Vsync   8 Vback    6 Vpol N

    Display Product Name: 'Color LCD'

    Dummy Descriptor:

    Dummy Descriptor:

  Extension blocks: 1

Checksum: 0x72

----------------

Block 1, DisplayID Extension Block:

  Version: 1.2

  Extension Count: 0

  Display Product Type: Standalone display device

  Vendor-Specific Data Block (0x7f) (Apple), OUI 00-10-FA:

    Type: 3, Version: 1

    18 0f 28 17 00 00 00 00 00 00 00 00 00 00 00 00 '..(.............'

    00 00 00 4c 50 31 33 33 57 51 35 2d 53 4a 41 37 '...LP133WQ5-SJA7'

    0a 20 00 44 43 4e 31 33 30 32 30 30 32 58 50 58 '. .DCN1302002XPX'

    47 54 41 4b 0a 20 20 20 20 20                   'GTAK.     '

  Vendor-Specific Data Block (0x7f) (Apple), OUI 00-10-FA:

    Type: 2, Version: 1

    00 11 00 00 02 90 03 65 04 89 06 18 08 38 0b 20 '.......e.....8. '

    0f 19 14 8a 1c 00 26 3d 34 51 47 ae 62 5a 87 21 '......&=4QG.bZ.!'

    b9 e3 ff 7d                                     '...}'

  Checksum: 0xb3

Checksum: 0x90

      devilgrove

      I tried this (with dither=0) on my Early 2015 13“ MacBook Pro with an Intel GPU and felt no difference in eye strain unfortunately.

      log show --predicate "processID == 0" | grep Dither

      Does not return anything

      nvram -p | grep dither

      returns boot-args dither=0

          devilgrove

          Can you give us more details about your macbook model please?

          You said 16".

          Which year?
          Which GPU?
          Which OS version do you have?

          Thank you

              karut I also have the MacBook Pro 13'' 2015 but it doesn't have dithering by default. And yes, log show --predicate "processID == 0" | grep Dither

              returns nothing.

                  NewDwarf

                  Interesting…I assume you also run the latest version of OSX Monterey. I will test the MacBook with an external monitor. The display should at least have no PWM according to Notebookcheck.

                    caboy my MacBook is actually a 16,2 meaning it's part of the 16th generation of MacBook Pros.

                    It'a a 2020 13" 4 TB3 running Catalina 10.15.7. It uses Intel Iris Plus from the Ice Lake generation.

                        NewDwarf

                        From what I can tell, the display panel is LG. Denoted by: LP133WQ5-SJA7

                        Looking online at the closest match to that model number it seems to be an 8-bit display (16.7 million colors). https://www.lcdsolar.com/products/ProductDetail.aspx/LGDISPLAY/LP133WQ1-SJA2/43520

                        I think the line with Bits per primary color channel: 10means that the GPU is a 10-bit GPU.

                        Thank you for posting and for your research finding a possible solution. I ordered a refurbished Macbook Pro Intel and will test when it arrives.

                        [Edit to add]

                        The LG panels previously gave me really bad eye strain (in 2012 models and others). This gives some hope. Thank you.

                            devilgrove Update to this:

                            I disabled AppleIntelICLGraphics.kext and AppleIntelSlowAdaptiveClocking.kext, and the display is now exactly like Safe Mode (as far as I'm aware). The only problem with this is that the display rendering is just as slow and just as glitchy as Safe Mode as well. Not sure if this is usable for me in the long run, but for those who can use Safe Mode but want full access to their Mac, give this a go.

                            Also, I have a rough idea of how I would go about trying to keep Safe Mode-level strain while being able to speed up the rendering. AppleIntelICLGraphics.kext is broken down into four bundles: The GLDriver, MTLDriver, VADriver, and VAME bundles. My theory is that I could disable or modify a combination of these bundles and keep ICLGraphics.kext enabled so that the render is back to normal speed. If anyone has ideas it would be appreciated, thanks.

                            Edit: too many applications required the use of OpenGL / Metal to run properly, so I reloaded AppleIntelICLGraphics.kext. I'll try to think of another solution (if there is one).

                                caboy

                                I think the line with Bits per primary color channel: 10means that the GPU is a 10-bit GPU.

                                No. According to the EDID specification, this is "Basic display parameters". So, this parameter is not related to the GPU. Primary colours are Red, Green, Blue. So each primary colour can be sampled by 210 levels.

                                  caboy yeah, it's still there unfortunately, but it's way more usable. My old configuration (which was like 10-15 different things going on in the setup) was a 4-5/10 in terms of pain. This is like a 1.5/10, and for the most part uses macOS on its default settings other than the nvram argument, color profile, and font smoothing. I even have the resolution on default now, versus having to use the non-HiDPI resolution before. I'm gonna try to find a true 8-bit display to hook up my MacBook to so that I can test if it'll get rid of the last bit of strain.

                                    ryans I would say the same answer as devilgrove, eyestrain improved from 4/10 pain to 1/10. Problem is that the banding is completely the same as before (at least on my MacBook Pro) so we have no objective way to prove it's not placebo and that it has a real effect

                                        ryans Additionally, you can try to change gamma of the screen in the expert mode. It also has some effect.

                                        https://discussions.apple.com/thread/8167595

                                        But I use the predefined "Display P3" colour profile. BTW, my laptop has the LG screen. Probably, users will have another experience with the Samsung screens.

                                        And, yes, I can confirm that I absolutely happy when dithering is disabled on my laptop.

                                        …recently I bought the avalanche photodiode and I am going to build new very sensitive application to measure high frequency PWM on low brightness.

                                          13 days later

                                          My 2017 13 inch MBP without Touch Bar shows dithering is disabled by default running Catalina 10.15.7 (19H2026). This laptop running this OS doesn't bother me.

                                          The output is:

                                          2022-11-02 16:04:11.497027-0400 0x3cd      Default     0x0                  0      0    kernel: (AppleIntelKBLGraphicsFramebuffer) [IGFB][INFO   ] [Modeset] Dither is disabled with bpc 1

                                          The ioreg command listed above doesn't show much, but manually searching the output text file of ioreg -lw0 for IODisplayEDID shows a value of 1552 for my DisplayVendorID key. I don't know which vendor that is.

                                          The system profiler output for this display is:

                                          Intel Iris Plus Graphics 640:

                                          Chipset Model: Intel Iris Plus Graphics 640

                                          Type: GPU

                                          Bus: Built-In

                                          VRAM (Dynamic, Max): 1536 MB

                                          Vendor: Intel

                                          Device ID: 0x5926

                                          Revision ID: 0x0006

                                          Metal: Supported, feature set macOS GPUFamily2 v1

                                          Displays:

                                          Color LCD:

                                          Display Type: Built-In Retina LCD

                                          Resolution: 2560 x 1600 Retina

                                          Framebuffer Depth: 24-Bit Color (ARGB8888)

                                          Main Display: Yes

                                          Mirror: Off

                                          Online: Yes

                                          Automatically Adjust Brightness: No

                                          Connection Type: Internal

                                          Have people in general had a better experience with the models that up until recently did not support P3 color gamut? The two thunderbolt port 13 inch MacBook Pro that did not have the Touch Bar never supported it. It’s my recollection that that model continued to not support it up until the M2 changeover. I’m not as familiar with the MacBook air line but I think it’s similar.

                                          dev