I originally posted this as a reply but I am moving it here instead as it warrants its own thread.

I've been using a Surface Pro 4 here and there since it launched in 2015. It's actually always been a relatively "inoffensive" screen compared to others, but I've noticed it's consistently become less and less easy on the eyes over the years with every Windows and driver update

i5 model, 8GB RAM, Intel HD 520. There's a chance the information in this post is only applicable to the i5 model as the i7 model has Intel Iris graphics instead - YMMV

It's of course affected by the infamous flickergate (screen shakes up and down when overheating), annoying battery drain, and general performance issues just like every other SP4, so along with the reduction in comfort it's been left mostly unused over the last few years. It also has obvious terrible 200 Hz PWM at everything except 100% brightness which is something I've always been affected by (even before I knew I was sensitive to PWM)… or at least I thought it needed to 🙂

However, recently, I've been able to significantly improve the display and make it surprisingly usable. Although I generally dislike glossy HiDPI panels, the Samsung PLS panel used in the SP4 is very unique in that it is one of the ONLY bright and color-accurate (100% sRGB!) panels that I am still able to use with very low strain! There's also a high chance that it's actually true 8-bit 👀 (don't take my word for it though)

IMHO, there is no reason why screens needed to "improve" at all beyond what is in this SP4. It's plenty bright, crisp, contrasty enough, and very vibrant and looks so much nicer to me than any modern tablet or smartphone display, even in the traditional sense of "visual appeal" to a common user.

As far as I know (flickergate aside), HiDPI displays peaked with this tablet and have only gone downhill since…

Here is what has improved the SP4 so far -- still on Windows 10 22H2 19045.4529! (Win10, not 11)

  • Remove modern Intel HD driver with DDU and downgrade to December 2015 driver (20.19.15.4352)
  • Disable DPST with dpst-control -- Intel FeatureTestControl is currently 8A10
  • Disable all video post-processing in Intel HD Graphics Control Panel
  • Disable temporal dithering with ditherig.exe
  • Disable WindowsColorSystem Calibration Loader service in Task Scheduler
  • Prevent any future Windows, driver, store updates, and maintenance tasks with Winaero Tweaker
  • Set non-acrylic taskbar style with Winaero Tweaker
  • (Optional) Individually set apps to "System" DPI scaling in compatibility settings to achieve "True Non-Retina" pixelated integer scaling wherever possible -- Firefox works with this (alternatively use SmartUpscale if you want to keep the browser semi-HiDPI), Electron-powered apps like VSCode can also work but need hardware acceleration to be disabled in each app's own settings. Disable font smoothing & web fonts to make Firefox look crisp at low-DPI
  • Work around 90% of flickergate issues by hackily disabling Panel Self-Refresh through enabling seconds on the system tray clock and setting a slightly smaller than native custom resolution (with aspect ratio scaling set to Center Image to avoid blur)

At this point, the screen finally felt like it did in 2016 again, even on 22H2. The only thing that still remained a huge issue was 200 Hz PWM. But as it turns out, that can actually be fixed (!!)

Yesterday, I found the app PWMHelper which is actually able to control PWM frequency on some laptops with Intel graphics. For a while I had the impression that similar apps like IntelPWMControl were only able to function on extremely ancient Intel chipsets, but this app seems to be compatible with a very good amount of modern-ish hardware

While filming the screen at low brightness in 240 Hz slow motion, I ran PWMHelper.exe 10000 to raise the PWM frequency all the way up to the maximum allowed 10 kHz. Almost magically the flicker disappeared from the recording. The only thing that remains on camera is the very thin vertical lines that typically indicate high frequency PWM

After everything I've done and especially this PWM fix, the SP4 is now yet another Windows device (and modern LED-backlit IPS panel) I have been able to salvage!

I am finally able to confidently say that this Surface Pro 4 is better for vision health than ANY iPad. Even my old 2011 iPad 2 🙂

It even proves that the much-hated Samsung PLS & Oxide TFT can actually be GOOD with the right software ‼️

Since this is all working on Windows 10 22H2, this means that all of the post-processing weirdness I experienced on Windows 11 23H2 on the ThinkPad T480 but not Windows 10 possibly does not affect Windows 10 versions in general. Or… another possibility is that the older Skylake graphics in the SP4 lack some functionality that prevents whatever strain-causing technique from activating on Win10 22H2 on the Surface, but Win10 22H2 possibly could still cause issues on the T480's 8th gen that e.g. 1809 wouldn't.

All I know currently is that Windows 11, especially Win11 22H2+, should be avoided on Intel graphics at all costs. Windows 10 seems to be necessary to have a chance at getting comfortable output. I technically haven't tried Win11 on the Surface but I don't want to risk it LOL. Same with keeping the T480 I'm evaluating on 1809 for now.

    I'll report back again after doing some more heavy work on this computer but so far, it literally seems like PWMHelper.exe 10000 fixed most of the remaining eye strain on the Surface Pro 4. The slight blurriness that I always used to feel (that weirdly, would only go away in the past if Intel drivers were disabled) seems to be totally gone now even when I have graphics drivers enabled.

    It's so satisfying and beautiful to finally have some way to experience a very high-contrast, detailed, and vibrant image without disorientation or immediate strain and with almost no "false 3D effect" (something I noticed the SP4 has always been good at preventing!)

    My experience here also possibly proves that raw intensity of color might actually not be an issue for me/us, as long as software "enhancement" or PWM is not messing with it.

    For example, the "Post Reply" button on this site is extremely bright green on the SP4, but after all of these fixes, it doesn't really feel like it's "drawing my eye to it" or "popping out of the screen" at all, I can simultaneously focus on the text I'm writing -- or even something as precise as the white gap to the right of the button -- without getting distracted or feeling like my "eyes are being pulled". The Reply and Follow buttons feel like they're almost at the exact same depth to me even though they are very different colors. I can still see the bright green color at the same time it comfortably remains in my periphrial vision. It's a really unique feeling.

    I used to frequently get little bursts of pain in my eyes when abruptly wanting to look left or right on the SP4, or after refocusing, but that literally hasn't happened yet today.

    The screen also used to always have a very "washed out" look that would keep increasing the longer I used it similar to a badly LED-lit room at anything under 100% brightness (because of PWM) but I'm not feeling that almost at all anymore. Colors remain just as vibrant after an hour of use.

    The pixelated style text I've achieved with "true non-retina" Firefox + forcing system fonts for hinting (combined with PWMHelper eliminating the flicker in slow-motion recordings) looks so crystal clear -- it is extremely reminiscent of how text looks on the original early-mid 2000s Nintendo DS and DS Lite systems (which have always been my go-to examples for screens that have never bothered me at all. I have a feeling the panels on those systems do not apply any image enhancement or color management at all).

    What's especially nice for me is that NoMachine screen sharing into a Mac also takes on the "true non-retina" look by default, because NoMachine does not support HiDPI.

    8 months later

    reaganry my ThinkPad now has a different, replaced AUO TN screen (AUO B140XTN02.D) which is sufficiently comfortable for me along with graphics drivers disabled — it is now many times better in comfort than the Surface was.

    However, the ThinkPad's original Innolux IPS screen is terrible, yes, and the Surface Pro 4 was more tolerable compared to it. Fortunately, ThinkPads have a really easy screen replacement process, so that's what I did.

      8 days later

      DisplaysShouldNotBeTVs Its strange, how PWM could be reduced or increased by the app, without affecting brightness also ?

        dev