I'm testing as many MacBooks as possible. Here are the results.

GBowler What graphics card is currently used? Did you choose the Radeon card as a default graphics card?

NewDwarf yes I used your command above gpuswitch 1

does the readout look like it's been successful do you think? really appreciate your help

GBowler Could you share the screenshot of Apple logo -> About this Mac?

GBowler And the second thing I would like to ask to do is

1. Reboot your laptop

2. Run the command log show --process 0 -last 15m | grep ahkinject

3. Check if the output of the previous command has similar output, the kernel extension works fine:

   2023-01-22 0x278      Default     0x0                  0      0    kernel: (ahkinject) AHKinject: attempting to disable dithering on AMDFramebuffer

   2023-01-22 0x278      Default     0x0                  0      0    kernel: (ahkinject) AHKinject: found a service

   2023-01-22 0x278      Default     0x0                  0      0    kernel: (ahkinject) AHKinject: successfully set attribute on connection 0

   2023-01-22 0x278      Default     0x0                  0      0    kernel: (ahkinject) AHKinject: found a service

   2023-01-22 0x278      Default     0x0                  0      0    kernel: (ahkinject) AHKinject: successfully set attribute on connection 0

   2023-01-22 0x278      Default     0x0                  0      0    kernel: (ahkinject) AHKinject: found a service

   2023-01-22 0x278      Default     0x0                  0      0    kernel: (ahkinject) AHKinject: successfully set attribute on connection 0

thankyou I'll have to do this first thing tomorrow as the laptops at my office,

The about this Mac page has the Radeon card above the intel btw.

but yes I'll do this first thing and post back, thanks!!

GBowler I have been investigating reports of eye strain on MacBooks being triggered by a firmware/OS update. I also bought a few tools to dump and flash different firmware versions on MacBooks (specifically testing the MacBooks I have, which are mid 2015 15-inch Pro models, both with and without the discrete AMD GPU). So far I cannot pin down the issue, but there have been several reports like yours and I plan to keep investigating. A GPU VBIOS update seems the most plausible.

I wonder if you can compare your non-symptomatic MacBook to the symptomatic one and report back further differences? The devices have identical configurations and exact OS versions? You reported already the different firmware versions; I am also curious about any GPU differences in the System Information app (especially ROM revision, gmux version, EFI driver version, etc.), SMC/BridgeOS version, the specific EFI firmware versions, etc. Anything you can observe/report may be insightful. I would love to pin down the specific update causing the issue, and whether it may be reversible.

Also see this MacRumors post about one user's eye strain which began with a specific subversion of macOS Catalina.

MAS-76 Has this worked for you 2019 16" (not 15") MBP?

@NewDwarf that didn't work for some reason, it gave the following;

log show --process 0 -last 15m | grep ahkinject

log: unrecognized option `--process'

usage: log show [options] <archive>

   or: log show [options]

description:

    Show the contents of the system log datastore or a log archive.

    Output contains only default level messages unless --info and/or

    --debug are specified.

options:

    --[no-]backtrace              Control whether backtraces are shown

    --[no-]debug                  Control whether "Debug" events are shown

    --[no-]info                   Control whether "Info" events are shown

    --[no-]loss                   Control whether message loss events are shown

    --[no-]signpost               Control whether signposts are shown

    --color <mode>                Control color output (valid: auto, always, none)

    --end <date>                  Display events up to the given end date

    --last <num>[m|h|d]           Display recent events up to the given limit

    --[no-]pager                  Paginate output using less.

    --predicate <predicate>       Filter events using the given predicate

    --source                      Annotate output with source file and line-number

    --start <date>                Display events from the given start date

    --style <style>               Output format (valid: default, syslog, json, ndjson, compact)

    --timezone local | <tz>       Use the given timezone when displaying event timestamps

    --mach-continuous-time        Print mach continuous time timestamps rather than walltime

valid time formats:

    'Y-M-D H:m:s+zzzz', 'Y-M-D H:m:s', 'Y-M-D', '@unixtime'

predicate usage:

    Filter predicates follow the NSPredicate format described at:

    https://developer.apple.com/library/content/documentation/Cocoa/Conceptual/Predicates/AdditionalChapters/Introduction.html

    For predicate field/type details, see `log help predicates`.

Btw I think it would interest everyone to say I am actually using the new Dasung Paperlike Color and I've been working on my non symptomatic MBP all morning, having just switched to the symptomatic one I can see the general overall image is way different I need to find time to post this and take photographs of the differences I'm seeing.

@macsforme my comfortable MPB has Bootrom: 1037.147.4.0.0 | iBridge 17.16.16610.0.0.0

uncomfortable identical MBP: Bottom 1968.100.17.0.0 (iBridge: 20.16.4252.0.0,0)

I spoke to someone at Apple and gave up in the end but he was saying that was the only difference in the machine aside from the fact that my comfortable one was bought in the UK and uncomfortable one turns out to be a US Machine.

GBowler Then just omit --process 0

and enter such command after rebooting your laptop:

log show -last 15m | grep ahkinject

NewDwarf thankyou!! I have no clue about these Terminal commands

Yes I got a long read out very similar to the one you shared! so it has worked thank you!!!

There seems to be something other than dithering going on that is giving me symptoms (this is all connecting to a 10bit Eizo monitor btw)

Really appreciate your help and it is good to know that dithering may not be the sole thing I need to focus on!!

macsforme Yes I've just checked and the Graphics/Displays details are identical between the two!

And I'm going into an Eizo 10bit external monitor

So it seems to be this Bootrom, I spoke to a guy who was advertising on eBay and he said he could replace the chip, is it the EFI chip? and that I just needed to give him the firmware version, I think it was around £300 so I think I may try that as an experiment.

On a total tangent I'm finding the Dasung Paperlike Color to be super helpful, tough going to get used to but I managed a half day video editing on it this morning!!

GBowler My understanding is that for Macs up until around 2017 (where I am focusing my research), the firmware/ROM is on a ROM chip which is accessible for read/write using a diagnostic port on the motherboard and a special cable and programmer. So, you can dump the ROM, extract the necessary parts and inject them into an older ROM update file (from Apple), then flash that back to the motherboard. I have done this a few times. Notably, the main firmware/ROM is only one component of several which can be updated, but this is where I have focused so far.

For later Macs, my understanding is that BridgeOS runs on the T2 chip, and like an iOS device you can only flash an older BridgeOS while Apple is still signing it (so only recent versions). I believe the firmware/ROM resides on the main SSD with the OS and user data, but the NAND flash is encrypted by the T2 so I do not see how you can manipulate it (other than perhaps erasing the entire NAND flash chips). You can use Apple Configurator 2 to "revive" or "restore" the firmware and operating system, but again, only recent versions still signed by Apple. So, I am curious if this person can actually flash an older firmware version on a T2 Mac, and whether that includes the BridgeOS.

GBowler Do you check on the external monitor? The problem is the external screen can be PWM enabled.

NewDwarf I haven't read much about PWM at all compared to dithering, so potentially these two MBP could be sending different pwm frequency to the monitor?

Lauda89 When you took the measurements with your Opple LightMaster, did you test the same color for both devices? I'm guessing you tested a brighter color (like white) for the Macbook and a dimmer color (like gray) for the gaming PC.

It would be best to use the same colors for both. And also to try using a handful of different colors, comparing the same color on one device with the same color on the other device.

Here's a handy page that lists all 256 shades of gray, red, green and blue. Obviously you don't need to test all 1000+ colors, but testing 20 different colors might produce interesting results. https://pixelinversion.com/AllColors.html

Also, it would be interesting to see the waveform from your iPhone X. 99.5% modulation depth is pretty crazy for a screen.