Some higher HiDPI resolutions do not work with high refresh rate modes in Seqouia on some Apple Silicon Macs (+ additional limitations with HDR enabled)

[goodnotgreat-ai]

updated to macos sequoia using m2 macmini and the monitor is lg cx48,it doesn't work with HiDPI mode selected at 2550x1440 and 120hz refresh rate

[teodoradriann]

mine doesnt work either

[waydabber]

Sequoia introduces stricter limits for M1 and entry level Macs especially in HDR mode. Try to disable HDR, reduce refresh rate or go for a lower resolution.

[goodnotgreat-ai]

HDR is not turned on. Under the conditions of 120 Hz and HiDPI, only 1920x1080 mode works normally. Does this mean that it can only be downgraded to macOS Sonoma?

[rchybicki]

same here, m3 max mbp, had 4k 120hz hidpi on sonoma, now can only do 60hz, huge downgrade

[rchybicki]

Yes exactly, that's what I used on Sonoma

[rchybicki]

Hi @waydabber, were you able to test if 4k 120hz HiDPI is working on your M3 Max on Sequoia? I'm still stuck on 60hz to get HiDPI.

[rchybicki]

I'm not sure what changed, but I can now select HiDPI 4k 120hz again. Came with a BetterDisplay update? I'm not sure, but I'm happy :-) Needs configuration protection to stay on.

[waydabber]

Strange. These options do not appear in the proper system mode list but only in the unexposed refresh rate list. Not entirely sure why that is though. Some more investigation might be needed.

Do you have 120Hz in System Settings/Displays?

[rchybicki]

Sadly, this was some sort of fluke. Selecting HIDPI on 120hz is dropping the resolution again now. With HIDPI on I can only select 60hz in Settings.

[MrUltimate]

Same here, before Sequoia, I was able to run 3440x1440@240hz and HiDPI. Now when I try to do that, I'm forced to a lower resolution. Clearly the hardware can support it, I don't see why Apple would enforce something like this?

[MrUltimate]

I had to drop to 120hz to achieve 3440x1440 with HiDPI. Clearly the hardware can support it so there's absolutely no reason why Apple would be enforcing something like this. @waydabber I hope you're able to find a way around this!

[kelvin-du]

I used to have 3840x1600@144hz with HiDPI. But now this option is gone. I can only use 3840x1600@144hz in LoDPI.
This happened right after I upgraded to MacOS 15.0

[DUEJIiST]

I have the same problem, before the update it worked 3440x1440@165Hz, got out of the situation by demoting the hertz to 120 while it works at 3440x1440, otherwise it demotes to 2048x858. Try dropping to 120 or below, maybe it will help.

[kelvin-du]

Hi, it worked at 3840x1600@120hz.
And I think it used to be like this (120hz) before the macOS upgrade.

[teodoradriann]

for me it doesnt work 3440x1440@120, i have to lower it to 100

[DUEJIiST]

I think the difference between 120 and 100 is not very noticeable, at least for now I think it is possible to work like this, it is better than on LoDPI :)

[openclosure]

Same thing here. After update to 15.0 I'm stuck at 3840x2160@95hz HiDPI instead of the previous 3840x2160@144hz HiDPI I was getting on Sonoma. Using an LG 27GN950-B. Tried creating a custom EDID with 120hz, 110hz, etc refresh rates but it seems it doesn't like anything except 95hz. This is all SDR-only on an M1 Mac. @waydabber would you have any suggestion for getting it to 120hz? Above you seem to imply that this does work for your M3 Max which gives me hope 🙏

[openclosure]

FYI to anyone frustrated with this issue on M1, I found a more acceptable tradeoff between refresh rate and scaling by doing the following:

• The big issue for me was that my monitor only offers 95hz or 144hz.
• Choosing 144hz means I'm stuck with scaling at 3008x1692 or 4K LoDPI, which is too big of a compromise for me.
• Choosing 95hz means I get full 4K w/ HiDPI but is also not ideal, for me the refresh rate is perceptibly worse.

Finding a Better Tradeoff

• Using AW EDID Editor and Video Timings Calculator, I created some new EDID with 120hz, 110hz, etc. (Use CVT-RB column on video timings).
• I enabled Enable flexible scaling in the BD menu (I had forgot about this setting).
• I found that with 110hz I get the max scaling of 3584x2016 or 187%. This is pretty good - actually not very noticably different from the full 200%. I also don't notice the refresh rate drop as much compared to 95hz. I think unless I played with it side by side, I don't notice.
• Set EDID to auto-apply

This issue is pretty annoying/frustrating, something that worked fine for several years now disabled by Apple. I submitted feedback and emailed [email protected] about it, you should too. But hopefully this satisifies until I get M4 or whatever.

@waydabber just to check, using M3 Max, is it possible to get the original 144hz back? Or are ALL models now capped at 120hz?

[tpstevens]

I'm running into a similar issue with Sequoia on an M2 Pro Mac Mini, a 3440x1440 display, and SDR. I used to be able to get HiDPI with a variable refresh rate of 60-165 Hz, but now I have to scale it to 98%.

I can still get HiDPI at 100% resolution scale and a static 144 Hz, but switching to a variable refresh rate (like 60-144 Hz) results in a display bug where the 80% of the expected image gets stretched across my monitor and I have to reset the resolution from the system settings menu.

[MetinYalcinkaya]

Same issue, M3 Pro, 4K 144hz + 1440p 144hz. Could use HiDPI before the update, now I have to drop to 60hz to be able to use HiDPI at native

[waydabber]

Hmm. That is very interesting. On an MBP with M3 Pro chip? How are the displays connected?

[MetinYalcinkaya]

Yup MacBook Pro w/ an M3 Pro. The 1440p monitor is through Thunderbolt, the 4K is through HDMI

[theospa]

Same issue here. 3840x1600, was running fine with 144hz HiDPI before, now it drops to 3360x1400. Reducing the refresh rate to 120Hz at System Settings helps to get 3840x1600 HiDPI, but would be nice to have 144hz. Did anyone find a workaround?

[waydabber]

Yes, there is a workaround you can try. Change to the desired resolution at 60Hz and then try the unexposed 120Hz refresh rate in the Refresh Rate menu. This works for some.

Here are some more info:

https://forums.macrumors.com/threads/dp-usb-c-thunderbolt-3-4-to-hdmi-2-1-4k-120hz-rgb4-4-4-10b-hdr-with-apple-silicon-m1-m2-m3-now-possible.2381664/post-33542051

[rchybicki]

Hey that does work, thanks! On my mac this trick works with 119.88hz and not 120hz for some reason.

[tobyjones-digital]

This workaround worked on my M2 Pro MacBook Pro. On Sonoma I was able to run my Dell G3223Q at 4k @ 120Hz with HiDPI mode without any workarounds, but after the Sequoia update I could only do 4K LoDPI at 120Hz, or 4K HiDPI at 60Hz. Using BetterDisplay to set the refresh rate to 119.88Hz worked to allow HiDPI at 4k120 again:

I have flexible scaling enabled in BetterDisplay settings, not sure if this makes a difference or not as it's something I tried whilst trying to troubleshoot. My monitor is connected to my Mac via the DisplayPort output on my CalDigit TS3 Plus Thunderbolt dock, if that makes a difference.