New attempt to disable dithering on M1/M2 chipsets

NewDwarf

Last attempt to disable dithering on M1/M2 devices failed.

Today I spent more time to reverse engineer the Apple silicon drivers.

Could you try to enter to command from the normal mode and check effect of this command:

sudo nvram boot-args="iomfb_disable_dfr_display=1 iomfb_force_block_Dither=1"

enter your password and then reboot the laptop.

JesHD

Thank you, NewDwarf !

I entered your command (MacBook Air M2).

Command

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

shows that:

2023-01-24 01:31:52.026676+0300 0x41b9 Default 0x0 0 0 kernel: (Sandbox) System Policy: nvram(3507) allow boot-arg-set iomfb_force_block_Dither

Need time for testing.

Is there any way to further check that dithering is off?

Display mode will remain 10 bit?

Ruoma

NewDwarf Hi there, very interested if this would work.

Do you have an m1 m2 to machine to test this on yourself?

Can anybody confirm this works? Is there a more detailed manual on how to do this for non coders?

Can I try it in the store using terminal for instance?

JesHD

NewDwarf After several days of testing (M2 Air Monterey), I still feel eye strain (using different profiles, sRGB IEC61966-2.1 and others). Maybe try some other commands?

ryans

I hope someone with this device can try it. Much thanks for keep working on this @NewDwarf 🙂!

Do you expect this might work on Ventura as well? Or must be before Ventura.

NewDwarf

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

Above command doesn't work for Apple silicon GPU. It is only Intel specific.

iomfb_disable_dfr_display env variable should skip default initialization for some GPU parameters specific to color management.

ryans

@bkdo Try the commands in the first post here, see if it helps on your M1 / M2.

MTNEYE

thanks @NewDwarf, ive been following this intently. I just tried to new command. will report back tomorrow morning. Usually notice the dithering feeling then. Is there a way to check if the command was run in terminal?

Edit: just ran the command and rebooted and a swear the screen looks better/different running the same sRGB IEC61966-2.1 profile. Was wondering, in a P3/sRGB example image like this one https://webkit.org/blog-files/color-gamut/comparison.html. Obviously if I keep my sRGB IEC61966-2.1 profile I shouldn't be able to see the differences in the image. Now, if I run the command and set the profile to P3 display, should it still mimmic 8 bit color and prevent me from seeing the differences? When I it now, P3 profile and the above dithering command run and rebooted, im still seeing the differences in the images.

edit 2: I had previously disabled “csrutil disable” in recovery mode when trying the original method you posted. was wondering if I could re-enable “csrutil" after entering this command?

MTNEYE

JesHD @NewDwarf I'm feeling it as well unfortunately

JesHD

MTNEYE maybe I need to enter this command again and testing (SIP is disabled)