This one doesn't make sense to me. The laptop is a Dell Precision 7520. Detailed specs are below. It has an Intel HD Graphics 530 iGPU and Nvidia Quadro M2200 dGPU.

It gives me bad headaches in the Win 10 desktop environment. It supposedly has a hardware mux switch, and disabling the iGPU (uncheck "Enable Switchable Graphics" in the BIOS) makes the headache severity even worse.

Confusingly, when I am playing a DirectX 11 game (Mechwarrior Online, I have not tested other games), I don't get any symptoms in fullscreen mode. Playing in fullscreen windowed mode produces the same headaches.

I know I am generally sensitive to PWM, and using this tool makes the headaches from the desktop environment slightly better: https://github.com/tpurtell/PWM. The tool reports a PWM frequency of 200. Adjusting the monitor calibration to slightly reduce contrast and adjust the colors and gamma has slightly helped.

I was hoping that since I didn't get headaches in game, disabling the iGPU would fix the issue. Unfortunately, it doesn't. Is there some Windows setting I'm missing?

I've played around with various tools to disable dithering (https://kawamoto.no-ip.org/henteko/myapp.html#ditherig) but it didn't seem to make a difference.

I have another laptop, an old Thinkpad T440s, which I tolerate fine in the desktop environment, that is running the same build/update version of Win 10. There were some copies of that laptop with different panels that I couldn't tolerate, however.

Another strange thing is that when I had a bad case of the flu, I didn't notice the headaches (???). Maybe the pain from the flu was just masking it.

EDIT: even more confusing, after trying out some peripheral gaze stretches, and some 'magic eye' images, the headaches seem reduced? https://old.reddit.com/r/Strabismus/comments/11sqoxn/recovering_binocular_vision_in_adulthood/

Device name

Processor Intel(R) Core(TM) i7-6820HQ CPU @ 2.70GHz 2.70 GHz

Installed RAM 32.0 GB (31.9 GB usable)

System type 64-bit operating system, x64-based processor

Pen and touch No pen or touch input is available for this display

Edition Windows 10 Pro

Version 22H2

Installed on ‎9/‎30/‎2024

OS build 19045.4894

Experience Windows Feature Experience Pack 1000.19060.1000.0

    You have the opportunity to try an external monitor to understand whether the screen is the problem or problem is hardware related ( either screen or MB/iGPU, or both )

    dyungim
    Maybe this would help:
    -run screen at full brightness
    -downgrade video drivers
    -set the Nvidia RGB dynamic range to limited
    -adjust windows visual effects for best performance(keep smooth edges of fonts)
    -disable WindowsColorSystem Calibration Loader service in Task Scheduler
    -disable nvidia gpu scaling in bios if you have the option
    -disable wifi/bluetooth in device manager

    DirectX 12 is what Win10 uses. Specifically Direct Write and Direct Draw 12. It is the cause of many of our symptoms on these symptoms. PWM/flicker/dithering is mostly a red herring that people focus on. The problem is almost never hardware related but software rendering related

    When you run the game it is running in a DirectX 11 mode which is not accessing the features of DirectX 12 that cause our symptoms.

      ensete You can disable some DirectX features with this registry entry:

      disableDirect3D.reg

      Windows Registry Editor Version 5.00
      
      [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DirectDraw]
      "EmulationOnly"=dword:00000001
      [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Direct3D\Drivers]
      "SoftwareOnly"=dword:00000001
      [HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\DirectDraw]
      "EmulationOnly"=dword:00000001
      [HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Direct3D\Drivers]
      "SoftwareOnly"=dword:00000001

      enableDirect3D.reg

      Windows Registry Editor Version 5.00
      
      [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DirectDraw]
      "EmulationOnly"=dword:00000000
      [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Direct3D\Drivers]
      "SoftwareOnly"=dword:00000000
      [HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\DirectDraw]
      "EmulationOnly"=dword:00000000
      [HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Direct3D\Drivers]
      "SoftwareOnly"=dword:00000000

      Remove registry entries altogether:

      Windows Registry Editor Version 5.00
      
      [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DirectDraw]
      "EmulationOnly"=-
      [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Direct3D\Drivers]
      "SoftwareOnly"=-
      [HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\DirectDraw]
      "EmulationOnly"=-
      [HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Direct3D\Drivers]
      "SoftwareOnly"=-

      Does it do anything for you?

        Staycalmsyndrome

        Do you know how to disable DX12.2 features? I found all bad devices are 12.2 compatible, all my old devices are 12.1 maximum

          simplex Try to run this registry tweak and see if you notice a difference. You can check if the features are disabled by typing "dxdiag" in the run command window and by checking the display tab.
          I think DirectX is so baked into the system that there isn't an easy way to entirely disable it.

          Staycalmsyndrome

          It might be too early to tell, but I don't think I notice a difference.

          Does the "remove entries altogether" file return the registry to its pre-modified state?

            ensete

            I did some more testing. I get symptoms when fiddling around in the BIOS settings UI. Does this use DirectX 12?

              dyungim Yes. Also, if you get symptoms in BIOS, try downgrading it to an older version.
              Maybe test an external portable monitor.

                • Edited

                Staycalmsyndrome most motherboards disallow bios downgrade. The way around it is to manually flash using a cha341a and extracting the body file from the capsule bios file. Its all very easy to do though

                  Staycalmsyndrome

                  Thanks. I guess what I don't understand is if it was a DX12 problem, would it show up using the BIOS settings UI because of this?

                    dyungim Does this use DirectX 12?

                    new BIOS use UEFI GOP video driver (old use VGA mode). How it works is blackbox

                    dyungim The UEFI BIOS uses a basic graphics output protocol(GOP) that also changes with every BIOS update. Don't know how much DirectX is involved. By default it's using the integrated intel iGPU GOP. If you uncheck "Enable Switchable Graphics", it will ask to restart and instantly switch to the nvidia GOP(like plugging your monitor from one video card to another).
                    Skylake machines are considered pretty 'safe' but they need tinkering.
                    Have you always had problems with this laptop or just recently? Maybe a windows update triggered it(they also do bios updates). Some users reported a relief by downgrading to Windows 10 1809.

                      jordan Last time i downgraded a Dell laptop i had to do it to the penultimate version and so on. But yeah, they might have locked it down. No fun allowed.

                      Staycalmsyndrome

                      I just started using it a few weeks ago and have always had problems.

                      Strangely, after doing some peripheral gaze stretches, my headaches are less intense, but still significant.

                      The plan is to try external displays eventually, but I have ME/CFS, so life goes very slowly for me. These videos explain the situation. Long story short, testing an external display will be a several months' project for me.

                      Post-exertional malaise and the importance of pacing: https://www.youtube.com/watch?v=TGIo1v7KVJQ

                      Short video describing PEM from a patient: https://www.youtube.com/watch?v=l1ufdoV5vYY

                      Short documentary describing CFS from a patient: https://www.youtube.com/watch?v=dUrPFqGONM8

                        dyungim Thank you for the clarification and sorry to hear this. Be sure to use maximum brightness and not that pwm app. Do you have the technical know-how to downgrade Windows or dual-boot? If you type 'msinfo32' in the run command window what BIOS version does it say?
                        I would just change the laptop with something similar in configuration but not Dell.

                          Staycalmsyndrome

                          I could downgrade or dual boot but it would take me a couple weeks. I think my current plan is to try for an external monitor, since in theory if I find one that works, at least I can use it in the future to eliminate the display as a variable.

                          BIOS Version/Date Dell Inc. 1.37.0, 7/4/2024

                          If I'm limited to purchasing from Costco, do you have any idea if I'd have better luck trying for a cheap small TV or going for a monitor? I have a feeling that in general for external displays, it's better to try a handful of displays with fundamentally different technologies instead of a bunch that have similar technologies at first.

                          What is the harm to using the PWM app? I am always using max brightness.

                            dyungim I was talking about one of these portable monitors that you could use to cover the internal one. If you're setting the screen on max brightness does the app alleviate the pain even further? I wouldn't play with PWM settings outside of specified ranges but that's just me.

                              dev