M1/M2 flickering, ghosting with external display [Merged]

[Timbit]

Think I might have a bit of a unique situation here as I'm having the same issue on multiple computers running macOS, including on a Hackintosh! (which is using an Intel processor).
- Hackintosh with Intel Core i9, Radeon RX Vega 64
- Mac Mini M1
- MacBook Air M1

FYI I am running two Philips 328E1CA 4K monitors. I have tried various HDMI cables as others have, but it did not help.

The fact that I see the problem on both Intel & M1 machines would indicate to me it's NOT an M1 hardware issue. Additionally, in my Hackintosh, I am using a Sapphire Nitro Radeon Vega 64 (not Apple hardware), and the issue still presents itself. I can dual boot into Windows for games and never see this issue, so nothing's wrong with the video card. To me, it definitely seems like a software issue since there is no Apple hardware in this Hackintosh 😅

I actually started seeing this a few months back on the Hackintosh, before I ever plugged an M1 mac into these monitors. But I kind of figured it was just some glitchy Hackintosh thing. I don't remember exactly when I first noticed it, but I would wager it started happening after I upgraded to Big Sur – I was running Catalina for a long time and definitely did NOT see this issue until maybe the last 6 months or so. So when I received my M1 Mac Mini and plugged it into the same monitor I was quite frustrated to see the problem again!

Another interesting thing: on my Hackintosh, I have one monitor connected via DisplayPort and the other via HDMI. Then I can mirror my displays. If I find a "spot" (ie. a certain position on a webpage) that reproduces the problem on the HDMI-connected monitor, it does not appear on the mirrored DisplayPort-connected one. And vice versa. Not sure what to make of it, but it's interesting nonetheless.

I wonder if there are two problems:

1. Vertical lines/flickering issue - this happens on all my machines running macOS)
2. Problems with M1 detecting external monitors correctly - this happens on only the M1 machines (See notes #3 - #5 below)

Other notes:

1. Tried plugging monitors into a different power source in case of some ground-loop issue, made no difference
2. Tried different cables of different lengths & manufacturers, did not help
3. I noticed my monitors only enable the overscan option when using the M1 input, not the Hackintosh (Radeon) input. Seems like the M1 is sending a signal the monitor things is for a TV?
4. On the Hackintosh, the serial number for the display shows up in System Information for the DisplayPort connected monitor, but not the HDMI one. On the M1 it does not show a serial number (connected via HDMI)
5. On the Hackintosh, it appears to correctly detect the display as a HiDPI display. In system information, it shows resolution as 2x the "UI Looks like" value (aka HiDPI mode). On the M1, the resolution and "UI Looks like" values are the same. The Hackintosh also has a "Framebuffer Depth" property set to 30-bit color. The M1 does not have this property
   
   View attachment 1948602

Here are a few photos I took of the problem:

vs without the problem:

And then on the M1 Mac mini

vs without the problem:

 

[oz_rkie]

Think I might have a bit of a unique situation here as I'm having the same issue on multiple computers running macOS, including on a Hackintosh! (which is using an Intel processor).
- Hackintosh with Intel Core i9, Radeon RX Vega 64
- Mac Mini M1
- MacBook Air M1

FYI I am running two Philips 328E1CA 4K monitors. I have tried various HDMI cables as others have, but it did not help.

The fact that I see the problem on both Intel & M1 machines would indicate to me it's NOT an M1 hardware issue. Additionally, in my Hackintosh, I am using a Sapphire Nitro Radeon Vega 64 (not Apple hardware), and the issue still presents itself. I can dual boot into Windows for games and never see this issue, so nothing's wrong with the video card. To me, it definitely seems like a software issue since there is no Apple hardware in this Hackintosh 😅

I actually started seeing this a few months back on the Hackintosh, before I ever plugged an M1 mac into these monitors. But I kind of figured it was just some glitchy Hackintosh thing. I don't remember exactly when I first noticed it, but I would wager it started happening after I upgraded to Big Sur – I was running Catalina for a long time and definitely did NOT see this issue until maybe the last 6 months or so. So when I received my M1 Mac Mini and plugged it into the same monitor I was quite frustrated to see the problem again!

Another interesting thing: on my Hackintosh, I have one monitor connected via DisplayPort and the other via HDMI. Then I can mirror my displays. If I find a "spot" (ie. a certain position on a webpage) that reproduces the problem on the HDMI-connected monitor, it does not appear on the mirrored DisplayPort-connected one. And vice versa. Not sure what to make of it, but it's interesting nonetheless.

I wonder if there are two problems:

1. Vertical lines/flickering issue - this happens on all my machines running macOS)
2. Problems with M1 detecting external monitors correctly - this happens on only the M1 machines (See notes #3 - #5 below)

Other notes:

1. Tried plugging monitors into a different power source in case of some ground-loop issue, made no difference
2. Tried different cables of different lengths & manufacturers, did not help
3. I noticed my monitors only enable the overscan option when using the M1 input, not the Hackintosh (Radeon) input. Seems like the M1 is sending a signal the monitor things is for a TV?
4. On the Hackintosh, the serial number for the display shows up in System Information for the DisplayPort connected monitor, but not the HDMI one. On the M1 it does not show a serial number (connected via HDMI)
5. On the Hackintosh, it appears to correctly detect the display as a HiDPI display. In system information, it shows resolution as 2x the "UI Looks like" value (aka HiDPI mode). On the M1, the resolution and "UI Looks like" values are the same. The Hackintosh also has a "Framebuffer Depth" property set to 30-bit color. The M1 does not have this property
   View attachment 1948606 View attachment 1948602

Here are a few photos I took of the problem:

View attachment 1948594
vs without the problem:
View attachment 1948596

And then on the M1 Mac mini
View attachment 1948599
vs without the problem:

View attachment 1948598

Hey, thanks for your detailed post. I would be interested to know if you are only experiencing the lines/flickering issue or have also experienced the image burn-in/retention issue as well?

 

[Timbit]

Hey @oz_rke, I have not seen the burn-in/retention issue. I have seen the ghosting issue, but so far only noticed it on the M1 machines.

 

[Josasp]

Think I might have a bit of a unique situation here as I'm having the same issue on multiple computers running macOS, including on a Hackintosh! (which is using an Intel processor).
- Hackintosh with Intel Core i9, Radeon RX Vega 64
- Mac Mini M1
- MacBook Air M1...

Previous to my Mac M1 I was running these displays on a MacBook Pro 2014 with a RX Vega 64 connected over thunderbolt without issues.

 

[Timbit]

@Josasp Which version of macOS was running on the MacBook Pro 2014? It seems like the problem is Big Sur in combination with certain monitors.

Like you, I also notice it is affected by color profile, night shift, or Flux. But as you said, it doesn't fix the issue but just moves it.

But I have definitely seen and still see the issue on my Hackintosh so I don't see how it can be specific to M1. There must be some other common thread between all of us that are experiencing this issue...

 

[Josasp]

@Josasp Which version of macOS was running on the MacBook Pro 2014? It seems like the problem is Big Sur in combination with certain monitors.

Like you, I also notice it is affected by color profile, night shift, or Flux. But as you said, it doesn't fix the issue but just moves it.

But I have definitely seen and still see the issue on my Hackintosh so I don't see how it can be specific to M1. There must be some other common thread between all of us that are experiencing this issue...

I was running Big Sur on that machine before retiring that setup.
It was with that GPU but with a Huawei Matebook I produced the issue once in Windows when it automatically and wrongly set the refresh rate to 59hz, setting to 60hz resolved the issue that time.

I remember thinking: "Crap, has my HDMI cable gone bad?"
Checked the settings, fixed the refresh rate, all good.

Was a cheap crappy cable that had taken a lot of abuse over the years.
So sort of expected it to fail at some point, but no.
It was just refresh rate settings in Windows.

 

[kToni73]

Any changes with the new update?

 

[The Reason]

Any changes with the new update?

Still happening for me.

 

[Kermisbrian]

Hi guys, i had the same problem with the 32uk500 monitor on a M1 mac mini.
I had a call with apple today and we found out if you put the black stabilizer on 0 the flickering disappears.
So go to the settings of your monitor settings/ picuture / game adjust / en than black stabilizer on 0.

Look like to work for me !

 

[Tek5]

Hi guys, i had the same problem with the 32uk500 monitor on a M1 mac mini.
I had a call with apple today and we found out if you put the black stabilizer on 0 the flickering disappears.
So go to the settings of your monitor settings/ picuture / game adjust / en than black stabilizer on 0.

Look like to work for me !

Thanks for your comment and great that it worked for you!
From my testing I can confirm that changing the black stabiliser level really helps. However (at least for me) it doesn‘t solve the problem completely, it only shifts the color/color range at which it occurs.
I never tried to set the level to 0 before though, so maybe then it really doesn‘t happen again.
But unfortunately, even if this would solve it, I just couldn‘t deal with it, because I gave it a go just now and the image quality is complete garbage (everything seems to be overexposes to an unbearable degree and all black colors look washed out).

It‘s insane that Apple hasn‘t acknowledged this problem yet properly and done something about it.

 

[SA22C]

It's weird, because I can adjust settings like the black stabilizer level and it'll work for a while but the flicker always comes back. And then I can reset all display settings to factory and the flicker will again go away for a while before coming back. It's very inconsistent.

 

[44sunsets]

Re-iterating my setup:
14" M1 Max MacBook Pro, running macOS Monterey 12.0.1
Dell S2721QS 4K monitor, connected directly via HDMI
(I mostly run this with the MBP lid closed, so the Dell monitor is the only active display)

Update: as of today, it's been four weeks since I've had any flickering/ghosting problems, so I'm pretty confident that the problem is now resolved for me. I'm not sure exactly what fixed it, but it seems to be either one of two things:

1. Updating to macOS Monterey 12.1
or
2. I upgraded to an HDMI 2.1 "8K" cable, instead of using the stock HDMI 2.0 cable that came with my Dell S2721QS monitor. It wasn't anything special, just a cheap Baseus cable that's rated for 4K/120Hz use (my monitor only supports a maximum of 60Hz refresh though) -- it's not VESA certified or anything like that.

Instinct says that it might've been the new HDMI 2.1 cable that did the trick, but then again I did briefly still experience some flickering (thought not as bad as before) once or twice after I started using the new cable, but it's been 100% perfect and continuously glitch-free for 4 weeks since then.

*shrugs* it's still a mystery to me, but I'm glad it's over now.

 

[Kermisbrian]

Unfortunately the problem was back in a hour. Try also a 8K 2.1 hdmi but to see if it works for this screen as well but stil the same problem. i looks like if you have the problem and reset the screen thats the best solution untill apple fix the problem...

 

[kToni73]

untill apple fix the problem...

If they ever fix it ...

 

[zarino]

Just chiming in to say I’ve faced the exact same issue for the last 3 months:

• MacBook Pro (14 inch, 2021) connected to a Dell P2721Q over either USB-C or HDMI.
• Depending on the Mac’s color profile (see below), displaying large blocks of particular dark colours on the Dell screen causes what appears to be a flickering backlight (but is actually a flickering lightness value in the pixels across the screen).
• If the triggering image/colour isn’t removed from view, the flickering gets worse and worse, until faint vertical light and dark "pinstripes" start appearing across the screen, and whatever’s on screen at the time starts to get "burned in" (so, eg: if you move a window, its old position will remain faintly visible – some people call this "ghosting").
• By this point, the flickering, pinstripes, and ghosting will remain on screen even after the MacBook has been disconnected (and, say, the external display is displaying a picture from a different device, or from its own OSD or diagnostic mode). The only thing to do at this point is to wait for the artefacts to fade away on their own, which—depending on how long the triggering image/colour was on screen for—might take 10 to 30 minutes.

I first noticed the issue when visiting websites like this and this – sites with rich, dark background colours. I’ve also come across it when editing artwork in Photoshop and Affinity Designer. It’s not a web browser thing, as even a screenshot of the "triggering" website (opened in Quicklook, or Preview) causes the issue. I sent one of these screenshots to another user on this forum and they confirmed it causes the same issue on their display too.

Like many other people here, I was originally led to believe it was an issue with the Dell display, because the flashing/pinstripes/ghosting would continue to happen even long after the Mac had been disconnected. Surely, I thought, this must mean that it’s a problem with the display.

But from what other people have said in this thread, it seems the problem happens with all sorts of displays, from all sorts of manufacturers, and the only common thread is the Mac’s M1 chip.

(That’s not to say the displays are completely blameless here – maybe there’s some sort of standard that both the Mac and the displays aren’t following correctly, for example.)

In my case, the Dell P2721Q display is running firmware version M3F100. Its OSD settings:

• Brightness: 50% – changing this makes no difference.
• Contrast: 100% – changing this makes no difference.
• Input color format: RGB – changing this to YPbPr makes all the screen colours go weird (I assume I’d need to tell the Mac to switch to sending a YPbPr signal).
• Sharpness: 50% – changing this makes no difference.
• Response time: normal – changing this (to "fast") makes no difference.
• DDC/CI: on.

The Mac is running macOS Monterey 12.2.1, and is closed (so the built-in screen is turned off). System Preferences > Displays (for the DELL P2721Q, since the built-in screen is turned off) shows:

• Resolution: Scaled (middle option, "looks like 3008×1692") – changing the resolution makes no difference.
• Colour Profile: (my own custom profile).
• Refresh Rate: 60 Hertz – lowering this (eg: to 50) makes no difference.
• Night Shift: Off – makes no difference whether it’s On or Off.

Other things I’ve tried that have no effect:

• "Reset Color", "Reset Display", "Reset Personalisation", "Factory Reset" options in the display’s OSD.
• Switching between USB-C and HDMI connections.
• Switching between "Appearance: Light" and "Appearance: Dark" in System Preferences > General.

Things that do seem to have an effect:

• Changing the Mac’s Colour Profile to sRGB IEC61966-2.1 (other colour profiles might work too), and then reducing the display’s contrast setting (to 80%) to compensate – this obviously changes the Mac’s colour output away from my custom calibrated profile, but seems to avoid the issue, with my saved screenshot at least. It could be that there are still other "triggering" colours that I’ve just not yet discovered.

If it works long term, changing the colour profile still feels like a work around, rather than a proper fix – surely the Mac shouldn’t be causing these issues in external displays, no matter what colour profile it uses?

I’d be interested to know whether other people have tried switching to a different colour profile (like sRGB IEC61966-2.1) and whether that solved the problem for them or not.

 

[infernoguy]

The only way I've countered this is by turning on HDR. Otherwise, nothing else has fixed it.

 

[v0n]

As I mentioned in the mini section regarding the same issue - I pretty much cured the ghosting on my M1 Mini by connecting monitor through the external powered TB4 hub. Nothing else worked.

 

[Tek5]

As I mentioned in the mini section regarding the same issue - I pretty much cured the ghosting on my M1 Mini by connecting monitor through the external powered TB4 hub. Nothing else worked.

I‘d like to try this as well - can you please share which one you use? Thanks!

 

[The Reason]

As I mentioned in the mini section regarding the same issue - I pretty much cured the ghosting on my M1 Mini by connecting monitor through the external powered TB4 hub. Nothing else worked.

This did not work for me. I'm using the Razer TB4 dock at work, and before that was using a Belkin TB3 dock. Issue happens with both.

My 4K LG at home has no issues, but my slightly different model LG 4k at work is plagued by this issue.

 

[v0n]

I‘d like to try this as well - can you please share which one you use? Thanks!

Kensington TB4 hub from left hand side port on the mac mini, feeding monitor and three drives.

 

[44sunsets]

Update: as of today, it's been four weeks since I've had any flickering/ghosting problems, so I'm pretty confident that the problem is now resolved for me.

Update 2: it was too good to be true. After 6 weeks of zero problems, the flickering/ghosting problem has returned. UGH. No idea why it didn't happen for so long, when it was happening 2-3 times a week before. But now it's back again.

And I haven't changed anything, been using my MBP exactly the same way all this time.

So the problem is not fixed for me.

Disconnecting the 8K HDMI cable and plugging it back in right away seems to make the flickering gradually go away within 1-2 minutes. Hopefully it won't get any worse than this.

 

[jbaylies]

I too have been experiencing the vertical scan lines and flickering.

ASUS VP28U > Displayport > Caldigit TS3+ dock > 2020 M1 macbook pro w/ macOS 11.6.4

I've tried changing all the settings I can find but nothing fixes it, aside from making the blacks lighter, which can get ugly. I have not noticed any "ghosting" whatsoever.

 

[kToni73]

I'm sad that this is still a problem with so many people. The only thing that helped me is buying an expensive monitor (well expensive for me). LG32UN880 works good with the USB-C connection. It charges and delivers flicker-free signal.

Previously I returned 2 Monitors, both were 32" and 4K. Samsung and Dell.

Apple is definitely taking time with this one...

 

[jbaylies]

Could someone recommend an ultrawide that I could use via displayport with my Caldigit TS3+ dock that won't experience this issue?

 

[oz_rkie]

Could someone recommend an ultrawide that I could use via displayport with my Caldigit TS3+ dock that won't experience this issue?

I would be very interested to know as well. Preferably an ultrawide that is atleast 38"