Mac Studio M1 Ultra External Monitor Flickering

<<. Before anyone suggests that I read this or check that or change cable.... That has all been tried to death. >>

<< The 32" is connected via a good HDMI cable. >.

There sure are a lot of crappy HDMI cable out there. What you did NOT state is that the HDMI cable you are using is one of these:

HDMI cables you want for HDMI-only Displays (higher resolutions than 720p TV sets) are marked as Certified with an anti-counterfeiting tag and are labeled:

"Premium High Speed HDMI cable" or that + "with Ethernet" --OR--

"Ultra High Speed HDMI cable" or that + "48G"

Cables with No Certification tags are good for your standard 720p TV set, and not much more.

HDMI was invented for HD TV sets. it works great at its original resolution of 720i or 720p. At higher resolutions, it quickly develops issues that are complex to solve, and the cables and adapters required to solve are NOT intuitive.

<< the 27" via a thunderbolt cable. >>

To use a thunderBolt cable, the cable must be marked with the Thunderbolt symbol indicating it is certified cable. For use with displays at high resolutions, it must be shorter than 0.8 meters for Apple cables, shorter than 0.5 meters for brand-X cables.

<< Everyone says to change the cable or whatnot but it seems the issue persists for most of us. >>

yes but -- its not that you need a replacement cable, you need an ADEQUATE cable.

Cables 'shipped in the box' are notorious for being 'lowest bidder' cables, and unless it has a certification tag attached, it still may not be up to the job.

When running at HDMI 2.1 speed and resolution, HDMI switches to a signaling method very similar to DisplayPort, which is limited to one meter maximum length.

Hello. Have some odd flickering since a few days, like old graphic card bug. Especially when working in c4d, the viewport starts flicker, stromboscop style. Very bad for my eyes. Certainly not good for the graphic card. Apple macstudio m1 ultra 2022, Apple Studio Display 27p, Sonoma 14.4.1

Bad driver ?

Hello

For the display, Using the factory cables (Thunderbolt3).

Lowered the resolution to 2560x1440 so I can read texts. Preset Apple Display (P3-600 nits).

I have 1 USB-C hardrive connected to the Apple Display.

I do have an USB 3 hub/dock connected to macstudio back ports, to connect 1 keybord (previous apple extended) and 2 external USB hard-drives.

And a Wacom tablet connected to the other USB back port.

Finally 2 mini usb 3 / USB-C hard-drives disks.

Indeed at each OS update I have to disconnect the USB Hub at start-up or it goes in repair mode.

But until Sonoma I didn't have those glitches/flickers. If it is connected ?!

all USB-C shaped ports on the Mac Studio MAX processor are Thunderbolt ports.

The cable you have -- is it no longer that 0.8 meters for a genuine Apple ThunderBolt cable with the Thunderbolt trademark symbol on the cable? or no longer than 0.5 meters for a Brand-X Thunderbolt cable with trademark?

At 60 Hz refresh rate, the 5K Apple Studio Display consumes 25.92 G bits/sec of the nominal 40 G bits/sec Thunderbolt cable it is connected to. Practical limitations suggest it real capacity is more like 32 G bits/sec, so once you connect the display, it can not support an additional DRIVE. You should NOT be connecting a drive to that same port, except maybe a slow, rotating magnetic backup drive. Connect as many slower peripherals as you like, their sustained data needs are negligible.

Grif_

Although cable selection is by far the most frequent problem, you appear to have eliminated cables as an issue.

Next on the list is Variable refresh rate settings. When variable refresh rates are described, most users hear that the refresh rate could go even HIGHER than nominal under certain conditions. They appear to ignore the other half -- that your refresh rates could go far LOWER than nominal, and if you are sensitive to it, could produce flicking in the process.

To test, be sure you have selected a high FIXED refresh rate.

--------

On a regular horizontally-oriented display, Only the display itself -- not ANY other component in the process -- knows anything about Vertical. the display is made up of a huge Stack of Horizontal slices. Only when the are exactly the right length, do you "accidentally" get Vertical features.

Problems with Vertical artifacts are almost always caused by problems inside the display itself.

This happens with my Apple M1 Studio as well! I got this computer a year ago and love the way it runs but the flicker drives me absolutely insane. I use a 4K Dell Monitor. I've tried replacing and even buying new a new monitor to troubleshoot.

I've called Apple support multiple times and they tell me there's nothing they can do about it.

To know my computer is not just faulty makes me hope that this is something that can be fixed in an update. I fear that this is just a bug that comes with the computer. I am also sure that if you buy Apple's $2000 monitor it will not flicker. Nonsense.

Anyway, maybe if enough of us complain this issue can get resolved somehow. I would love Apple to at least acknowledge the issue considering a lot of people are having it happen. It tends to get worse when more windows are open or the screen gets busy and it's THE WORST!!!

Agreed this is a massive problem. This has been ongoing for years and Apple has not said a thing.

I'm going to report this to the FTC and the General Counsel of my state because I can't even use this technology without getting migraines. It's baffling how there hasn't been a recall of this yet.

I just want to chime in that this is still a problem. M1 ultra, Dell curved monitor, Hi-speed display port cable that I purchased separately and is not a lower end brand (I forget the exact brand, I've just dealt with the issue for about a year). I've tried both active and passive cables. I've done a similar amount of testing and swapping, same issues.

This issue also occurred with 2 other monitors that I've tried. It however does not occur on my crappy 1080p monitors.

Everything is within spec. Less than 10' cables. I believe 6' but it's been a while since I checked. I don't buy longer cables than are necessary. I've tried multiple resolutions, options, and refresh rates. Nothing changes. Darker screens always flicker. Which sucks because I prefer dark mode.

I said both active and passive in my original reply. Do you have a solution or just the same questions that have been asked?

Please assume that literally everything that has been suggested in this thread has already been tried. Are there any OTHER possible causes besides cables and settings? Is there some sort of apple firmware that can be requested or anything? This is not an external problem. This is absolutely an apple problem (likely with the chipset).

If there are extremely specific setups that need to be utilized, outline that, exactly, with all limitations and optimal setups. Something like:

"Use this adapter to go from thunderbolt to display port, use this length of cable from this brand, use these monitors at these refresh rates at these resolutions."