Variable Refresh Rate (FreeSync / GSync) Flicker

[CMMChris]

You can try using Better Display to dump your monitors EDID, edit the EDID (using AW EDID) to remove all YCbCr support and then upload the custom EDID to see if you can force RGB that way.
I am using that method to force 10-bit color depth on my current 4k screen which by default runs with 8-bit YCbCr on macOS.

 

[NGHTCRWLR]

Yep, done that. Just removes any choices for above 60hz.

Cable Matters has figured out the secret. They have developed firmware for their USB-C (DP) to HDMI 2.1 adapters to get 4K/120hz/RGB/10bit out of even M1 Macs. But it required a lot of work from their devs for Mac when the stock firmware did the exact same thing automatically for Windows for years now.

I'm not sure if they've actually said what it required, but it proves the TB/DP port is capable of the full bandwidth needed even if Apple is fighting it.

Apparently, this was only possible to do since Ventura, and some other places that have been trying to get RGB output for many years has said some monitors started RGB output suddenly after Ventura.

So Apple is slowly improving some things, but they certainly move at their own ridiculous pace.

 

[CMMChris]

Maybe worth taking a closer look at the EDID of this adapter.

 

[NGHTCRWLR]

Yep, done that too. Cable Matter's adapter has used two different chips from Synaptics over its lifetime. The older one the VMM6100 required a special firmware and a special EDID to work.

It has taken then a month or so to try and copy what worked about that firmware to this new VMM7100 chip, for some reason the same solution they expected to work wasn't doing it. But now they managed to provide a firmware only for the 7100 that no longer requires the EDID as well.

Have tried both EDIDs, in full and in pieces of what they changed to my monitor and it either again removes all choices above 60hz, or sometimes leaves all the choices but anything above 60hz falls back to 4:2:2.

CM has done a great job with this, if they could have provided this with only an EDID profile, I think they absolutely would have, as some customers have to jump through big hoops to be able to update the firmware on these adapters as it can only be done in Windows, and the 6100 only on a Windows machine that has a USB-C with DP port, which most Mac users do not have access to.

So I think they're doing some serious work in the firmware to get around the roadblocks Apple has set up.

 

[tarasis]

Has there been any improvements in the macOS 14 betas?

 

[CMMChris]

Nope

 

[tarasis]

Nope

Dang, cheers.

 

[CMMChris]

Maybe we will have more luck with macOS 174 Terra Sirenum 😂

 

[WestonHarvey1]

At this point the best solution appears to be buy a new monitor. Apple is never going to fix this.

 

[CMMChris]

Why would you buy a new monitor if you can just disable VRR?

 

[WestonHarvey1]

Why would you buy a new monitor if you can just disable VRR?

I can't disable VRR on my particular monitor. You can't permanently disable VRR from the macOS interface - your preference is not persistent. All the workarounds are janky - Automator scripts, scheduling command line scripts to run.

 

[CMMChris]

Ah well, in that case it sucks yeah.

 

[mecim06]

Hello. I plug my Mac book pro m1 with usb-c to display 1.2 cable to my samsung LC24FG73FQMXUF free sync monitor. Image quality is very good however after wakening my laptop, the sound which I get monitor with the hi-fi cable starts scrannel. When I prefer usb-c to hdmi 2.0, image quality and sound are good. What is the problem? Apart from that which one (display port 1.2 or cdmi 2.0) better for my laptop?

Thanks

 

[CMMChris]

This is off topic. Please start your own or post in a general bug collecting topic regarding your macOS version.
If you want to report your issue to apple, use https://feedbackassistant.apple.com/

 

[antareus]

You can edit your EDID to remove VRR support from it and then override it with BetterDisplay. I did that because my monitor doesn't have a way to disable VRR on it, and it seems to work fine: the VRR refresh rate option disappeared from the UI (as expected).

I had to use Custom Resolution Utility in Windows to edit it, unfortunately. The macOS EDID editors were too technical for me.

 

[Mr Screech]

Guys, I walked around it. It's dirty as hell but works.

Here's what's to do:

1. Install displayplacer utility

   brew tap jakehilborn/jakehilborn && brew install displayplacer

2. Manually set non adaptive-sync refresh rate you prefer in System Preferences
3. Call

   displayplacer list

   Remember your exteral monitor Presistent screen id. Look for arrow (<---) and remember mode index. In my case it was

   mode 253: res:3008x1692 hz:144 color_depth:7 scaling:on <-- current mode

4. Call

   crontab -e

5. Paste:

   */1 * * * * /opt/homebrew/bin/displayplacer "id:416B10C6-033A-010B-0857-D6964E3302DB mode:253"

   Use your monitor id and your mode index. For more info how to work with editor look for vim tutorial
6. Voila, test it. It'll flicker for up to 1 minute but should stop (blink, sorry)

This finally worked, thank you so much!
I tried automator, bettertouchtool, shortcuts, switchresx, cru, and no combination worked to automatically set the right Hz.

My only adjustment was to make it check every 5s instead of 1 minute. Since sometimes after the screen turned back on, it took too long to execute the script.

* * * * * /opt/homebrew/bin/displayplacer
* * * * * sleep 5; /opt/homebrew/bin/displayplacer
* * * * * sleep 10; /opt/homebrew/bin/displayplacer
* * * * * sleep 15; /opt/homebrew/bin/displayplacer
* * * * * sleep 20; /opt/homebrew/bin/displayplacer
* * * * * sleep 25; /opt/homebrew/bin/displayplacer
* * * * * sleep 30; /opt/homebrew/bin/displayplacer
* * * * * sleep 35; /opt/homebrew/bin/displayplacer
* * * * * sleep 40; /opt/homebrew/bin/displayplacer
* * * * * sleep 45; /opt/homebrew/bin/displayplacer
* * * * * sleep 50; /opt/homebrew/bin/displayplacer
* * * * * sleep 55; /opt/homebrew/bin/displayplacer

 

[phrehdd]

I used this long long ago to get a Mac Mini to work with a plasma tv properly....thoughts

SwitchResX - The Most Versatile Tool For Controlling Screen Resolutions On Your Mac

SwitchResX

 

[Sptzz]

G34WQC user here with a MBP 16 M3 Max. I noticed a bit of flickering, not overly massive but my desktop PC shows 0 flickering on the same screen. Using USB-C to DP 1.4 cable. PC also used regular DP > DP 1.4.

I literally just switched to 144hz on system settings and am golden. Also turned of FreeSync Premium on the monitors OSD just to be sure.

The flickering wasn't massive but on some overlays, like opening an image on Telegram showed flickering mainly on white images.

 

[pixelwave]

Mac Studio M2 Max (12C / 30C), Sonoma 14.4.1 + LG UltraGear 27GL850-B.

Connected via USB-C to Displayport 1.4 cable.

I have crazy flickering when I set refresh rate to 60, 100, or 144Hz.

When I select 120 Hz it is working.

Super weird. Has there been any fix yet?

 

[CMMChris]

The issue discussed here only applies to variable refresh rate, not fixed refresh rate. It's still not fixed. You are having a different issue when seeing flicker with fixed refresh rates.

 

[pixelwave]

Video of the issue (@144 hz):

https://imgur.com/a/8aSkHFP

I think still the monitor as some variable refresh sync active - at least I was not able to figure out how to deactivate it via the osd ...

 

[CMMChris]

If you select a fixed refresh rate in the macOS display settings, variable refresh rate is not being used, regardless if it's enabled in the monitor or not.

 

[pixelwave]

Ah ok ... so this is a new issue. Great.

But it seems they are all somehow related with the display output / driver. Since the flickering is also the same as with the VRR issue (see video).

 

[CMMChris]

Best thing to do is to file feedback with Apple (which they will likely ignore like all the others) and additionally trying to get in touch with LG.

 

[pixelwave]

I currently have the Mac Studio hooked up to a LG 32UD59-B. There the 60Hz works without flicker (same DP cable). With the LG UltraGear 27GL850-B it flickers at 60Hz.