I disabled dithering on Apple silicon + Introducing Stillcolor macOS M1/M2/M3

jordan

Wow that sounds very promising. So is this the 2022 MacBook pro 13" M2 then? Unsure if it matters but what ram/SSD is yours?

DisplaysShouldNotBeTVs

jordan Yep, it's the 13" 2022 M2 MBP with the touch bar and rectangular LCD (no notch).

I have 24GB RAM, 1TB SSD, Silver (which is $1609 USD refurbished — also, 8GB 256GB base model is $999)

BTW, to avoid PWM from the OLED Touch Bar strip, I used BetterTouchTool to set up a completely black touch bar with invisible black buttons to control brightness and volume.

async

DisplaysShouldNotBeTVs Awesome. Can you post the output of ioreg so I can compare / diff it to the M1 Max? Does it use the new MobileFramebuffer? Would be interesting to see exactly what features are different in how it renders things.

Note that this command contain personal information (name), so be sure to open it in a text editor first.

ioreg -lrbit -d0 -w0 -r -c AppleCLCD2 -a \
| sed -e '/^\t*<data>/,/^\t*<\/data>/ { /^\(\t*\)<data>\(.*\)/ { s//\1<string>_data:\2/; h; d; }; /^\t*<\/data>\(.*\)/! { s/^\t\(.*\)/\1/; H; d; }; /^\t*<\/data>\(.*\)/ { s//\1:data_<\/string>/; H; g; s/\n//g; }; }' \
| plutil -convert json -r - -o -

DisplaysShouldNotBeTVs

async here's my ioreg https://controlc.com/0c098e34/fullscreen.php?hash=858082fdcdd89e7b2b111fbed606224a

interesting:

the TCON is AppleParadeDP855TCON

"AppleARMPWM" : 2,

"AppleARMPWMBacklight" : 0,

"AppleARMPWMBacklightControllerUpdateFunction" : 0,

DisplaysShouldNotBeTVs

async

DisplaysShouldNotBeTVs Interesting. Comparing now. So apparently you have AppleSummitLCD, whatever that is. It's not there on my M1 Max. The only reference I found to it was here What happens when an M1 Mac starts up? – The Eclectic Light Company, but I didn't google much. Some H7DisplayPipe as well. And some references to debug device.

com.apple.driver.AppleMobileDispH14G-DCP vs com.apple.driver.AppleMobileDispT600X-DCP

It would be really interesting to do the same on an M2 Touch Bar with a bad screen.

karut

DisplaysShouldNotBeTVs

How do you access the function keys (F1-F12)?

Sentiny

DisplaysShouldNotBeTVs great overview. By the way, is there a chance that you just won “display lottery” with your M2 Pro TB?

Do we have other positive cases with this laptop?

jordan

DisplaysShouldNotBeTVs sorry I haven't been following every message here but does that screen still use FRC?

DisplaysShouldNotBeTVs

karut macOS by default makes F1-F12 show up on the touch bar (temporarily overriding my custom invisible touch bar layout) while the 🌐FN key is held. after FN is released, macOS automatically switches back to the custom layout

(BTW, on the M2 Touch Bar MBP the escape key is still a physical key, unlike some of the older Intel Touch Bar MBPs)

of course, the F1-F12 keys are rendered in apple's default touch bar UI with extremely flickery gray buttons, but this is only something you would be looking at for like 2 seconds before it switches back to black so it doesn't bother me

if you want to absolutely avoid PWM you could also set up some custom keybindings, like mapping alt-shift-1 to F1 for instance

DisplaysShouldNotBeTVs

Sentiny Yep, it's a nearly perfect panel in color uniformity.

No backlight bleed and has the legendary "reddish tint" that is usually associated with Apple's better manufactured screens instead of a hazy "greenish tint".

I'd definitely say I won the screen lottery with my second TB Pro!

However, even the lower quality yellow/greenish panel I got on my first TB Pro with visibly obvious screen defects was still wayyy more comfortable than all other Apple Silicon laptops, and didn't flicker on dark grays on camera either. White backgrounds looked way worse on it though and it was obviously not manufactured precisely at all. The color of white was totally different on the left side vs. the right side of the display. Of course, I returned it because I knew it could only get better from this.

On the other hand, the panel on my second TB Pro is PERFECT!! White backgrounds are pretty much as uniform as you can get with IPS.

Something really nice about the 13" M2 TB Pro is I swear it has the best keyboard travel out of all Apple Silicon laptops.

I hated the M1 and M2 Air keyboards (too little travel) and always felt the 14"/16" Pro keyboards were flimsy. I make so many typos on all of those. In contrast, the 13" M2 TB Pro keyboard is sooooo satisfying to type on, travel feels like double of what the Airs are like, and I type so fast. Closest I've ever felt to pre-2015 MacBook keyboard travel on a modern Mac.

In fact, both my first and second TB Pro have the same great keyboard, so it seems to be tied to the laptop's design itself and not just a keyboard lottery!

BTW, I posted the dumped panel IDs for each TB Pro in the "M2 Air screen flickering" thread.

DisplaysShouldNotBeTVs

async It would be really interesting to do the same on an M2 Touch Bar with a bad screen.

There's not really a M2 Touch Bar with a truly "bad screen" / unusable screen IMO, since even my first one with the worse panel was still more usable than every other Apple Silicon Mac. It was more of just visible defects, yellow tint, and screen uniformity issues which made me return that one.

(The "worse" panel had long empty sections of 00000000 in the panel ID and serial number dump, the "amazing" panel has a fully filled out serial number without any empty sections.)

However, since I still have the M1 Air for a little bit longer, I will dump ioreg on there — since I consider the M1 Air very uncomfortable (relative to any M2 Touch Bar Pro).

The M1 Air's panel is a lot different, flickers on camera (in the same way the M2 Air does) and is way worse.

Will be interesting to see if the ioreg has any significant difference.

photon78s

jordan

So I am testing a refurbished 13 inch M2 MBP with Touch Bar as mentioned by DisplaysShouldNotBeTVs. I disabled the oled touch bar which indeed flickers under my camera. Edit: While I did not detect any PWM on the backlight at 240fps or at 1/24000 shutter speed photos the opple shows PWM flicker at lower brightness settings (see below and PS). More testing on that later with oscilloscope waveforms.

Under the microscope, I'm surprised to find little pixel flicker. It's still there but if this is in fact pixel inversion or some kind of FRC, it is minor compared to the 7i at 60hz. Edit: I am always running Stillcolor with dithering disabled and uniformity2d disabled. It has comparable low levels of pixel level micro flicker to my T480s panel also running at 60hz. It is still too early for me to rank which is most comfortable (7i, T480s, or this particular MBP).

Update! FWIW, Opple waveform charts at 100%, 50%, and 25% panel brightness. At lower panel brightness their is more fluctuations unfortunately but still very good results at brighter settings. I would personally avoid 50% and lower brightness settings.

https://ibb.co/Z1CSt3k (100% full brightness)
https://ibb.co/pxqJ3GR (50%)
https://ibb.co/Btd5RW3 (25%)

Opple reports ~~the PWM frequency to range from about 41khz to 24khz and reports~~ "no risk" at the three tested brightness settings. The charts:

https://ibb.co/w6D7ZsF (100% full brightness)
https://ibb.co/jZPvCFz (50%)
https://ibb.co/865cMtP (25%)

Tested on white background for showing backlight PWM not temporal dithering.

Thank you DisplaysShouldNotBeTVs for discovering this "hidden" model and sharing!

PS: I should have noted to not take these absolute PWM frequency numbers too seriously from a measurement device like the Opple. See: https://ledstrain.org/d/2686-i-disabled-dithering-on-apple-silicon-introducing-stillcolor-macos-m1m2m3/741

madmozg

photon78s at notebookcheck website they are saying that MBP 13 M2 with TB is flickering if brightness <56%. Could you check that ? Looks like opple lightmaster could not detect that because the display is getting very dim.

madmozg

photon78s those pixels flickering is it on MBP 13 TB ? If yes, could you compare with Intel macbooks ? Just curious.

simplex

photon78s Opple waveform charts at 100%, 50%, and 25%

when I measure my 16" 2k 120hz laptop, I got results where Opple measure PWM freq equail to Screen refresh rate

At 120hz - 123hz PWM

At 60hz - 61hz PWM

At 50hz - 55hz PWM

At 48hz - 48hz PWM

I think, Opple dont show PWM coz it synchronise with refresh rate. And as lower brightness, as more noise in screen, so its hard to measure proper freq with Opple.

Look at your 25% measurments, dont you think its 8ms period and 120hz PWM?

DisplaysShouldNotBeTVs

photon78s Edit: While I did not detect any PWM on the backlight at 240fps or at 1/24000 shutter speed photos the opple shows PWM flicker at lower brightness settings (see below). More testing on that later with oscilloscope waveforms.

Yep this lines up with the notebookcheck review (which is good to know, since sometimes notebookcheck can be really inaccurate)

When I say the M2 TB Pro screen is "flicker-free" I mean it's possible to make it flicker-free, i.e. at higher brightness levels.

Also, I actually did use the computer for a while at lower brightness levels yesterday, and whatever high frequency PWM is there still does not affect me nearly as much as the really annoying low frequency PWM-like flicker on M1 Air and M2 Air.

However, PWM can still be avoided at high brightness!

(Lots of people think that is true with other Macs too, but two 2015 Intel Macs I tested actually also show PWM-like flicker on dark grays in 240hz slow-motion even at max brightness!

M2 Touch Bar Pro is the only MacBook I've tested that just doesn't have this issue at all. This is what makes it so unique!)

And with Stillcolor, it's possible to dim the screen through color overlays or color table adjustments (e.g. with BetterDisplay) without introducing temporal dithering.

photon78s

madmozg

I already did (see updated post) and the opple seems to show significant "modulation depth" and flicker. So for myself, I would use this close to or at full brightness in a brightly lit ambient environment.

madmozg

Well this thread is so big now, we probably would need some kind of wiki page somewhere. To post all the info and ways to go through logs, models, info and etc. Maybe we can use your repo and wiki page there at StillColor app ? @aiaf

madmozg

DisplaysShouldNotBeTVs I can agree with you. Thanks for the feedback, you should create a new topic with those assumptions also, so other people could find your info easily. 🙂

Btw I went yesterday to apple and did some testing for iMac M3, and I was not able to find any flickering, I need more time to do more tests before posting anything solid here.

photon78s

madmozg

Yes, pixel flicker on the MBP 13 TB while running Stillcolor with disable dithering and disable uniformity. Using 240 fps camera with microscope. I don't have Intel models to compare.

macsforme

async I'm 90% sure that I could do 6-bit with AW EDID Editor some time ago, however when trying recently the OS seemed to ignore it, like it does with certain things. I use this for 10 to 8-bit successfully. Figured it was either due to Sonoma upgrade, or that it simply didn't renegotiate or something.

See my post here for my own recent experiment involving an Intel Mac Pro, macOS High Sierra, an NVIDIA GPU, and a 6-bit+FRC display. While subjective, I definitely felt a difference (worse flickering, unstable image) when overriding the display EDID from 8-bit color depth to 6-bit color depth. Furthermore, other than while on the lock screen (and only on one display… weird), the effective depth did not appear to be reduced, so I figured all this did was traded the display's FRC dithering for temporal dithering by the operating system or GPU.

EDIT: Sorry, I just saw that you replied to that post, and therefore already saw it. Interesting that our experiences differ, though.

madmozg

photon78s got it! Thanks, what kind of lens are you using ?

photon78s

madmozg

Carson microflip at 100-200x magnification. To clarify, it is getting hard to distinguish if what I'm seeing is pixel flicker or just artifacts and noise from my Samsung 240 fps phone camera. On crappy displays and monitors, the pixel flicker absolutely obvious and "undulating". With this display, it's actually a very good sign that I'm having difficulty making clear interpretations.

On pixelinversion.com and I did not see flicker on the first page of tests. Also a very good sign.

« Previous Page Next Page »