5K2K at 120Hz with Mac Mini M4

[plantdadsunite]

Not available on the 5k2k/WUHD Dell U4035QW for example, with not quite matching aspect ration conversion

I guess my question is why is it not available? My guess is that Since macOS uses 2x scaling, a 4042px wide resolution would require an 8084px virtual screen, exceeding the 8k limit that macOS / these chips seem to have. Any other reason?

 

[DigiH]

I guess my question is why is it not available?

I really meant it when I wrote "not quite matching aspect ration conversion"

Your suggested 4042x1692 (from the native 5120x2160) has different conversion ratios for vertical and horizontal resolution 1.26669965 and 1.27659574. So it's not really making any scalable working sense

And taking a unified scale of 1.26669965 for example would then make the vertical uneven - not working on a pixel display … where did you get the 4042x1692 suggestion from for a 5k2k/WUHD?

While 3840x1620 has a proper 1.33333333 scale for both.

 

[plantdadsunite]

I really meant it when I wrote "not quite matching aspect ration conversion"

Your suggested 4042x1692 (from the native 5120x2160) has different conversion ratios for vertical and horizontal resolution 1.26669965 and 1.27659574. So it's not really making any scalable working sense

And taking a unified scale of 1.26669965 for example would then make the vertical uneven - not working on a pixel display … where did you get the 4042x1692 suggestion from for an 5k2k/WUHD?

While 3840x1620 has a proper 1.33333333 scale for both.

Doesn't 3440x1440 have this same issue, and is a standard scaled resolution for 5k2k monitors?

 

[DigiH]

Doesn't 3440x1440 have this same issue, and is a standard resolution for 5k2k monitors?

Just divide any horizontal and vertical resolution ideas you are wondering about from the original 5120x2160. Then see if the scaling matches or not.

I think you might be getting these ideas from other monitors with other aspect ratios.

 

[plantdadsunite]

Yes, I did calculate.
5120 is 1.488372093x 3440, while 2160 is 1.5x 1440.

You said

Your suggested 4042x1692 (from the native 5120x2160) has different conversion ratios for vertical and horizontal resolution

But 3440x1440 has the same issue, and seems to be a standard 5k2k scaled resolution. So this seems unlikely to be the reason.

Hopefully someone else can help us figure out what the issue is!

 

[DigiH]

But 3440x1440 has the same issue. So this seems unlikely to be the reason.

Yes, as you just showed in your calculation above.

5120 is 1.488372093x 3440, while 2160 is 1.5x 1440.

Or was the "But 3440x1440 has the same issue" a typo?

Either way, 3440x1440 is not working for exactly the reason of mismatched scaling.

 

[plantdadsunite]

Yes, as you just showed in your calculation above.

Or was the "But 3440x1440 has the same issue" a typo?

Either way, 3440x1440 is not working for exactly the reason of mismatched scaling.

Both 3440x1440 and 4042x1692 have different conversion ratios for vertical and horizontal resolution from the native 5120x2160, yet 3440x1440 is a standard scaled resolution for 5k2k ultrawides. So this reason (having different conversion ratios for vertical and horizontal resolution) is unlikely to be the issue.

 

[DigiH]

5120x2160, yet 3440x1440 is a standard scaled resolution for 5k2k ultrawides.

Then I might be missing something fundamental and totally misunderstanding the UI scaling requirements 😟

But the aspect ratios of 5120x2160 and 3440x1440 are also different, so possibly different ultrawides?

There you go

Best 5k2k [2160p] Ultrawide Monitors - ByteXD

The 21:9 aspect ratio is a popular choice for ultrawide monitors, providing a wider horizontal viewing area than traditional 16:9 monitors. However, not all

bytexd.com

suppose it depends which 21:9 flavour Ultrawide you have or want to get. Then it's likely either 3440x1440 or 3840x1620.

The important bit being

However, not all monitors marketed as 21:9 have the same actual aspect ratio.

 

[plantdadsunite]

I think you're actually right, and I was working off the wrong assumption of standard scaled resolutions. . MY BAD.

 

[Ed M.]

ASD is 5K (5120x2880)

5K2K is (5120x2160)

You’ll be losing 720 pixels (360 vertically top and bottom)

Cutting the 5K2K UW res in half gives you

(2560x1080 UW)

Then I came across this:

https://thinglabs.io/ultrawide-219-2560-x-1080-aspect-ratio

Which helps explain things a bit. Keep in mind that pixel density will be less and as the screens get bigger (while keeping the same resolution). Things just aren’t going to look as crisp and sharp. Lots of weird scaling especially if it’s not a whole number factor like 2, 3, 4…

 

[Ed M.]

And this is something else that I’m finding very informative:

Finding the Perfect Desktop Monitor for macOS and Windows: A Deep Dive into Size, Resolution, and Pixel Density – Wenz-Kim

wenz-kim.net

 

[ClassicMartini]

I think you're actually right, and I was working off the wrong assumption of standard scaled resolutions. . MY BAD.

On a 40", 5120 x 2160 monitor the UI (text size for) at HiDPI, 3840 x 1620 - Apple OS Menu Bar, Chrome Bookmark Bar etc, is in the goldilocks zone.

Not too zoomed in, and not too tiny.

5120 x 2160 native UI feels like trying to read 6 point type from 3 feet.

HiDPI, 3840 x 1620's UI menu scaling (down from 512o x 2160) basically feels like a 27" ASD, but sized up to a 40".

 

[andrwmai]

Dumb question on resolutions.

For 4k/UHD (3840x2160) monitors:

• 27" (163 PPI): scaled resolution sweet spot is at 2560x1440
• 32" (138 PPI): scaled resolution sweet spot is at 3008x1692

Translating that to 5k2k/WUHD (5120x2160) monitors (~1.34x horizontal resolution of 4K):

• 34" (163 PPI): scaled resolution sweet spot should be 3440x1440
• 40" (138 PPI): scaled resolution sweet spot should be 4042x1692

However, throughout this discussion I've seen 3840x1620 touted as the ideal resolution for the 40" ultrawides. Why is that?

Because the maximum horizontal pixels you can get on Pro/Max/Ultra chips are 3840px. It's the framebuffer limit since M1 and Apple hasn't raised it.

 

[Ed M.]

Pixels really don’t have a “size”, and a pixel on an iPhone or iPad Pro screen is going to be far smaller than a pixel (dot) represented on a billboard or 42” monitor for that matter and an 70” TV screen.

When you go from a smaller screen to a larger screen (while keeping resolution the same on both), you’re essentially “zooming in”. It’s the same thing—even worse if you’re going to a larger screen with lower resolution than one smaller screen but higher resolution.

The other thing I came across is that Apple disabled sub-pixel rendering since 2018 (Mojave) which likely exacerbates the situation with non-retina displays.

 

[Ed M.]

“…text looks fine in HighDPI panels (Retina Displays) but odd in StandardDPI (Non-Retina Displays)…”

From here:

https://www.reddit.com/r/hackintosh/comments/p6uin7/pro_tip_subpixel_rendering

The person offers a fix that some might try. YMMV.

 

[apple_lh]

No change in 15.2 😕

 

[don_simon]

No change in 15.2 😕

I too see no change in available resolutions. Anyone else?

 

[kasakka]

Dumb question on resolutions.

For 4k/UHD (3840x2160) monitors:

• 27" (163 PPI): scaled resolution sweet spot is at 2560x1440
• 32" (138 PPI): scaled resolution sweet spot is at 3008x1692

Translating that to 5k2k/WUHD (5120x2160) monitors (~1.34x horizontal resolution of 4K):

• 34" (163 PPI): scaled resolution sweet spot should be 3440x1440
• 40" (138 PPI): scaled resolution sweet spot should be 4042x1692

However, throughout this discussion I've seen 3840x1620 touted as the ideal resolution for the 40" ultrawides. Why is that?

Sweet spot is subjective and depends on the res, size and viewing distance.

I find 2560x1440 appropriate for my 28" 4K screen, but at the same viewing distance prefer 2880x1620 for the equivalent of a 32" 4K monitor, or in my case 3840x1620 for an ultrawide version of that.

The problem is that MacOS maxes out at 3840x1620 (7680x3240 render res), so 4042x1692 is not even an option. It's all about Apple's dumb **** scaling system.

Considering BetterDisplay can create virtual screens with pretty much any HiDPI res up to 16Kx16K afaik, MacOS doesn't have issues with actually handling them, so the issue seems to be entirely a hardware limitation, or one imposed by Apple where any render res above 7680x4320 is not possible.

 

[Ed M.]

Has anyone tried reenabling sub-pixel rendering on MacOS. Precious posted indicate that Apple has in fact disabled it an all current versions of MacOS. That should help with clarity issues. I’m currently running old 5K iMacs and soon to be running ASD so it would be better for someone to try it on non-retina screens to see if it makes any difference

 

[klambrec]

For anyone considering/holding off on an M4 Mac Mini because of the issues with the LG 40WP95C or other non-120Hz monitors, I'm happy to report that with the Mirroring functionality in BetterDisplay everything ended up working just fine at 3840x1620 and looks really crisp (on the base M4 Mini). The performance impact is basically non existent and it "just works". Do be sure to use the "virtual screen mirroring" and not the "full screen streaming" which I had enabled at first (and which is flaky).

I do hope that Apple will fix the native support for HiDPI at this resolution of course.

 

[rezwits]

Here is why you want TB5 i.e. Display Port 2.1:

Yes, DisplayPort 2.1 is capable of supporting 8K at 120Hz with HDR, but it depends on the configuration and compression settings:

1. Bandwidth: DisplayPort 2.1 offers a maximum raw bandwidth of 80 Gbps with a usable bandwidth of 77.37 Gbps after overhead. This makes it capable of driving 8K120 in certain configurations.

2. Compression:

• Without compression, 8K120 (10-bit color, RGB or 4:4:4 chroma) exceeds the available bandwidth, so it would require DSC (Display Stream Compression) to fit within the bandwidth.

• With DSC, 8K120 HDR is achievable and visually lossless.

3. Cabling:

• You would need a certified Ultra-High Bit Rate (UHBR) DisplayPort cable to utilize the maximum bandwidth of DisplayPort 2.1.

4. Hardware Support:

• Both the GPU and monitor must support DisplayPort 2.1 and be capable of handling the resolution and refresh rate.

In summary, DisplayPort 2.1 can indeed push 8K120 with HDR, but compression (e.g., DSC) will typically be required for this resolution and refresh rate combination.

Believe one thing, I have an old ATI 5770 on a MacPro 2008 and 2009 that can drive 4K60 i.e. 3840 non-HiDPI and 1920 non-HiDPI

But you never know if in 2-3 years you wanna just buy like a 54" an LG or Sony 8K120 OLED or MiniLed TV!

2¢ Laters...

 

[apple_lh]

For anyone considering/holding off on an M4 Mac Mini because of the issues with the LG 40WP95C or other non-120Hz monitors, I'm happy to report that with the Mirroring functionality in BetterDisplay everything ended up working just fine at 3840x1620 and looks really crisp (on the base M4 Mini). The performance impact is basically non existent and it "just works". Do be sure to use the "virtual screen mirroring" and not the "full screen streaming" which I had enabled at first (and which is flaky).

I do hope that Apple will fix the native support for HiDPI at this resolution of course.

what about the mouse, it keeps hanging with betterDisplay, that's irritating

 

[klambrec]

what about the mouse, it keeps hanging with betterDisplay, that's irritating

Not something I've experienced so far.

 

[Daveyboyeee]

Just an update. Been back and forth with Apple on this issue sending logs and screenshots. Last thing they told me was to keep the mini up to date… so hopefully a fix coming soon.

I also get the mouse lag with betterdisplay :\

 

[mctape]

For anyone considering/holding off on an M4 Mac Mini because of the issues with the LG 40WP95C or other non-120Hz monitors, I'm happy to report that with the Mirroring functionality in BetterDisplay everything ended up working just fine at 3840x1620 and looks really crisp (on the base M4 Mini). The performance impact is basically non existent and it "just works". Do be sure to use the "virtual screen mirroring" and not the "full screen streaming" which I had enabled at first (and which is flaky).

I do hope that Apple will fix the native support for HiDPI at this resolution of course.

After trying this for about 15 minutes this is working very nicely so far. Nice little hack! 😎

ETA: After using it all weekend, no complaints, performance has been great. The only nitpick is that when booting up my display (LG 34WK95U) is 3360x1418 until BetterDisplay loads, but that's just a few seconds, and nothing that anyone can really do anything about anyway.