Got a tip for us?
Let us know
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
DisplayLink Manager Updated With Native Support for M1 Macs and More
- Thread starter MacRumors
- Start date
- Sort by reaction score
It now works, though not always. I think the feature is still in beta. But it's a step in the right direction.
Heh. At second try, it didn't work.
Not clear to me how they implement it. I looked into killing DisplayLink when the screen is locked, then launching it again when it's unlocked, but could never quite figure out a mechanism.
I am asking you for an advice, maybe you know. This thing is I use SwitchResX and RDM.app on the New 16" MBP and they only give me 3456x2234, which is lower than the 3840x2400 that I get on my 15" which has inferior GPU and lower PPI.
So what do I need to tweak to get a higher resolution on the new 2021 MBP, that has a better GPU and a better display?
Last edited:
Your 15-inch is 2880x1800. The 3840x2400 you're picking are an interpolated, oversampled resolution; the display doesn't actually map that to real pixels.
That said, your new one probably also has scaled modes where you can pick hire, non-native resolutions?
It's supposed to have that, but the scaling apps (SwtchResX and RDM.app) only give me as much as 3456x2160 which is a bummer, these GPU and display are supposed to give me MUCH higher resolution.
How to achieve that?
I'm really not sure what you're up to there. If you would actually scale a laptop display to that resolution, the menu bar is incredibly & impossibly small and all UI elements become nearly unusable, fonts would lose all legibility. If you actually had scaled a 2880x1800 native resolution to an oversampled 3840x2400 and looking at it with that output, you couldn't use this forum to write that post. Nobody's eyes are that good.
Which makes me believe that that's not what you're doing. You may be confusing many concepts here. Please use (many) more words to explain your setup and goal, otherwise people will just talk past each other.
One more guess: You have actually been using one of those scaled resolution in which the system renders it INTERNALLY as 3840x2400 (these are not pixels you ever see!) and then it's pushed on your 15" 2880x1800 panel to appear as 1920x1200 resolution. And that would make more sense.
Now, if all that is true, then what you actually want to do is to forget about all this custom stuff. It's not meant for internal displays.
Those virtual pixels you're referring to in the 15" were never real, but a necessary software algorithm, akin to a hack, to make 1920x1200 look as sharp as possible with a 2880x1800 panel, yet not "Real 2x Retina Display" sharp. The new 16" M1 achieves a real 2x HiDPI without these hacks. That's why you don't see the unnecessary, quality-reducing and resource-wasting upscaling option to 3840x2400. You'd new and better panel doesn't need it.
Just pick one of the defaults from System Preferences that looks good to you. For any one you choose, the system will automatically (and invisibly) scale it up or down to your new and sharper panel. And because it has more DPI, there will be more real pixels. You can verify that with a microscope.
And if you don't take the time to understand that well, then I'm afraid you'll keep over-analyzing and chasing this ghost for a while! ?
Like Alan Watts said it: The menu is not the meal. 3840x2400 is a pointer to values in internal processing, not real pixels. Eat the meal, not the menu. Don't optimize the wrong thing.
You want a 3840x2400 scaled mode so that you can use the HiDPI mode "Looks like 1920x1200". If SwitchResX and RDM can't add the necessary 3840x2400 scaled mode (because Apple's artificial M1 Mac limits) then maybe https://github.com/waydabber/BetterDummy will work. BetterDummy might cap max refresh rate to 60Hz though and there might be a problem with display sleep?
https://forums.macrumors.com/threads/solution-quadhd-monitor-with-hidpi-and-mac-mini-m1.2303291/
https://forums.macrumors.com/threads/mac-mini-m1-external-display-scaling-option-hdmi-tb3.2270618/
https://forums.macrumors.com/thread...-display.2319072/?post=30515327#post-30515327
https://forums.macrumors.com/threads/better-solution-to-hidpi-qhd-on-m1-macbook-pro.2320165/
BetterDummy partially helps by giving me the desired "looks", but loses all the space to the left and right of the notch and taxes the system with a 2nd virtual screen.
If we ignore the downside of taxing the system by a 2nd screen, using BD makes sense (for my needs) only for very high scaling (because first you need to compensate for the loss of vertical space as I can't use use space to the left and right of the notch) options, that make UI elements even smaller than I would want to go. So BD will remain a niche app for me until/if they release an update that deals with the notch. Kudos to you for a great advice!
Last edited:
Are you saying that mirroring from the virtual display to the internal display doesn't draw to the left or right of the notch? Can you share a photo?
This means you need to know how many pixels the notch is, in order to choose a proper resolution for the virtual display?
Correct.
Attached!
How will this knowledge help me? As far as I understand, BD can only create a rectangle with almost any resolution, but it can't account for the notch (perhaps devs will add that later if enough folks ask them to). BD does not have 14:9, it only has 16:10, maybe 14:9 is what the devs need to add?
Attachments
Last edited:
We probably can't get the pixels around the notch - Apple needs to add a "include notch" option for mirroring (or can a third party do it?) - but we can choose the best resolution that matches the aspect ratio of the remaining pixels.
Your display is 3456x2234.
16:10 = 3456x2160
16:9 = 3456x1944
Maybe the notch is 74 pixels (2234-2160=74)? So maybe 16:10 is the best mode?
If you set the display to 3456x2234, then use "Scale to fit" for an app https://support.apple.com/en-us/HT212842 and take a screenshot, then what size is the screenshot? Maybe that can tell us the height of the notch. Or maybe take a screenshot of any app in full screen mode (do full screen mode and not full screen mode so they can be compared).
Some people may like that there's a way to hide the notch by turning the menu bar black:
https://forums.macrumors.com/thread...otch-these-apps-will-hide-it-for-you.2319849/
It does not even give me the "Scale to fit option", see printscreen
With the current limitations of the apps, I think I am going to use SwitchResX as a default scaling app (because it at least partially takes advantage of the ears and does not add a second screen) and go to BD when I need extreme scaling for something.
Attachments
I'm sorry if I was condescending in yesterday's post, @Appledoesnotlisten. Now that it's clear what's being attempted here (HiDPI custom modes for better font interpolation etc) ... not only it makes more sense, but I want it too. ?
Namely, the ability to run my 24" WQHD monitors at "Looks like" 2048 x 1152 resolution, but with a HiDPI rendering of 4096 x 2304 behind the scenes.
The difference should be quite apparent in this comparison. Those are screen shots from the same window, one running with HiDPI and the other without.
That was lost when I switched to M1 Air from Intel 16". I had to use a vanilla 2048 x 1152 resolution to get optimal UI proportions ... but then it was the panel's responsibility to do the sub-pixel rendering or whatever it has to do to stretch 2048 x 1152 pixels into a 2560 x 1440 canvas. Result: jazzy fonts, blurry details.
Anyway, thanks to @joevt I tried BetterDummy, and looks like it works. It's a bit of a hack, I wonder how this DisplayLink-enabled setup survives a reboot. Yet it's nice to see it works at all. Display Preferences now displays FIVE monitors, two of them virtual and stacked on top of the physical monitors.
LEFT MONITOR — WQHD 2560x1440 LCD, mirrored through BetterDummy:
Resolution: 4096 x 2304
UI Looks like: 2048 x 1152 @ 60.00Hz
MIDDLE MONITOR — LG UltraFine 5k:
Resolution: 5120 x 2880 (5K/UHD+ - Ultra High Definition Plus)
UI Looks like: 2560 x 1440 @ 60.00Hz
RIGHT MONITOR — WQHD 2560x1440 LCD, mirrored through BetterDummy:
Resolution: 4096 x 2304
UI Looks like: 2048 x 1152 @ 60.00Hz
Update 1: It does survive a reboot / undocking / re-docking. Somehow the OS, DisplayLink and BetterDummy remain in agreement about what the display resolutions, scalings and positions should be. That was a positive surprise.
Update 2: When undocking to laptop-land, looks like it's a good idea to quit BetterDummy, because otherwise the virtual screens become extended screens into nowhere, making it possible to lose the mouse cursor. There may be a workaround for that, but haven't figured an elegant one yet.
Namely, the ability to run my 24" WQHD monitors at "Looks like" 2048 x 1152 resolution, but with a HiDPI rendering of 4096 x 2304 behind the scenes.
The difference should be quite apparent in this comparison. Those are screen shots from the same window, one running with HiDPI and the other without.
That was lost when I switched to M1 Air from Intel 16". I had to use a vanilla 2048 x 1152 resolution to get optimal UI proportions ... but then it was the panel's responsibility to do the sub-pixel rendering or whatever it has to do to stretch 2048 x 1152 pixels into a 2560 x 1440 canvas. Result: jazzy fonts, blurry details.
Anyway, thanks to @joevt I tried BetterDummy, and looks like it works. It's a bit of a hack, I wonder how this DisplayLink-enabled setup survives a reboot. Yet it's nice to see it works at all. Display Preferences now displays FIVE monitors, two of them virtual and stacked on top of the physical monitors.
LEFT MONITOR — WQHD 2560x1440 LCD, mirrored through BetterDummy:
Resolution: 4096 x 2304
UI Looks like: 2048 x 1152 @ 60.00Hz
MIDDLE MONITOR — LG UltraFine 5k:
Resolution: 5120 x 2880 (5K/UHD+ - Ultra High Definition Plus)
UI Looks like: 2560 x 1440 @ 60.00Hz
RIGHT MONITOR — WQHD 2560x1440 LCD, mirrored through BetterDummy:
Resolution: 4096 x 2304
UI Looks like: 2048 x 1152 @ 60.00Hz
Update 1: It does survive a reboot / undocking / re-docking. Somehow the OS, DisplayLink and BetterDummy remain in agreement about what the display resolutions, scalings and positions should be. That was a positive surprise.
Update 2: When undocking to laptop-land, looks like it's a good idea to quit BetterDummy, because otherwise the virtual screens become extended screens into nowhere, making it possible to lose the mouse cursor. There may be a workaround for that, but haven't figured an elegant one yet.
Last edited:
Hey Guys,
I can add the nMBP 14/16 native resolutions to BetterDummy. The only issue is that these resolutions are rather unorthodox, their Greatest Common Divisor is 4 or 2 so it is difficult to neatly add a wide range of elegant resolutions that will match the exact aspect ratio of the display (but as far as I see, even Apple struggled with this and used approximations for additional modes, which is super weird).
I don't have an nMBP so I could not try this - I hope mirroring a display to the notched nMBP display will fill the screen, but it is almost 100% that macOS in general can't really handle the situation well when a dummy display is mirrored to the nMBP's screen with a notch (Apple might think that this is a rare - or nonexistent - use case and they are probably justified in this).
I can add the nMBP 14/16 native resolutions to BetterDummy. The only issue is that these resolutions are rather unorthodox, their Greatest Common Divisor is 4 or 2 so it is difficult to neatly add a wide range of elegant resolutions that will match the exact aspect ratio of the display (but as far as I see, even Apple struggled with this and used approximations for additional modes, which is super weird).
I don't have an nMBP so I could not try this - I hope mirroring a display to the notched nMBP display will fill the screen, but it is almost 100% that macOS in general can't really handle the situation well when a dummy display is mirrored to the nMBP's screen with a notch (Apple might think that this is a rare - or nonexistent - use case and they are probably justified in this).
Adding M1 Pro/Max MBP aspect ratio modes might not be a good idea if macOS won't draw into the camera area. We need to know the area that macOS will draw into and match that aspect ratio.
Well, you can already try what would happen with mirroring - just create a dummy that has a narrower aspect ratio than the nMBP ratio with notch included (try 1:1) and see what happens - does the mirror extends beyond/under the notch or the notch line is intact and the Dummy is mirrored beneath the Notch. If the latter, then this is a strong indication that things might not go well even with exactly matching the nMBP full (notch included) aspect ratio.
@Appledoesnotlisten,
here is a test version with added aspect ratios that are close to the 14" and 16" new MBP-s.
github.com
It would be great if you could try whether the mirroring fills the screen and sneaks beneath the dock or not. You can report back on the Dummy discord channel or the GitHub page as well, since this discussion seems to be offtopic here.
here is a test version with added aspect ratios that are close to the 14" and 16" new MBP-s.
Release v1.0.7c · waydabber/BetterDisplay
Added 2021 14" and 16" MBP asect ratio (approximation only due to wei…
github.com
It would be great if you could try whether the mirroring fills the screen and sneaks beneath the dock or not. You can report back on the Dummy discord channel or the GitHub page as well, since this discussion seems to be offtopic here.
I have the ASUS PQ321Q which supported MST on my 2013 MacPro trash can. In MST mode I could get 3840x2160 at 60hz. However, I just upgraded to a new Mac Studio and cannot get the ASUS display to work in MST mode anymore. I can only get half the display (1920x2160) to run at 60hz. I've tried every combination of Displayport/HDMI/USB-C combination I can think of but nothing works. I just tried installing SwitchRez but it's not showing me 3840x2160 @60hz as an available resolution. Would a Displaylink adapter address this problem?
Probably not. I know DisplayLink added a mode for dual link SST 5K but I don't know if they support MST 4K. You should explain your problem on the DisplayLink Forum.
https://www.displaylink.org/forum/index.php
There's a post for a similar display: https://displaylink.org/forum/showthread.php?t=66217
They would need to add firmware to support MST. It might not be possible. At least in the 5K case, the two streams are completely separate. But in the 4K case both streams need to come from the same DisplayPort output.