Comment by starkparker
1 day ago
Every 4K external display I've connected to every M1- and M2-series Mac running macOS has a known flickering issue with Display Stream Compression that Apple knows about and has been unable or unwilling to fix.
The only reliable fixes are to either disable that DisplayPort feature if your monitor supports it, or to disable GPU Dithering using a paid third-party tool (BetterDisplay). Either that or switch to Asahi, which doesn't have that issue.
The issue is common enough that BENQ has a FAQ page about it, which includes steps like "disable dark mode" and "wait for 2 hours": https://www.benq.com/en-us/knowledge-center/knowledge/how-to...
I use two 4k displays with an M1 Pro MBP. They work without any flickering. They’re using HDMI rather than DisplayPort.
I’m also, to get the two external displays without them being mirrored, using a docking station and a display driver from Silicon Motion called macOS InstantView.
This is of course not ideal if you need DP and DSC.
I have been experiencing this on my 2k monitors as well (Also BENQ). I tried every "fix" under the sun, eventually it stops after enough voodoo (reboots, unplugs) and cursing.
One of the many random issues on the OS with the best UX in the world (lol). Like music sometimes stopping and sometimes switching to speakers when turning off Bluetooth headphones, mouse speed going bananas randomly requiring mouse off and on, terminal app (iterm2) reliably crashing when I dare to change any keybinding, and many other things that never happened in years of working on Linux.
If you're looking for high quality text at 4K, your options are more limited than if you're looking for gaming. This is a good roundup, and the leading Dell is superb:
https://news.ycombinator.com/item?id=37025568
The best option was the LG UltraFine 24” 4K, which sadly was discontinued years ago.
In my opinion a QHD 23.8” panel is the next best option for developers (any M-series chip handles scaling without issues); I find the common 27” and 32” at 4K a weird spot - slightly too large, slightly too low resolution – and 5k+ options are still rare.
COMPLETELY agree. I still own and use those LGs.
One of my external screens is 4k and I haven't noticed any flickering. It's an Apple monitor though, so maybe that's the difference.
I've used ASUS 4K monitors on M2 and M4 machines without issues.
My Dell Ultrasharp 4K also doesn't flicker and has DSC enabled according to the on screen menu. At work there are a few old Iiyama 4K screens that flicker though, but I don't know if they even understand DSC.
1 reply →
> or switch to Asahi
I would like to point out that, from my experience on M1, external displays do not work at all over DisplayPort on Asahi Linux at the moment.