DisplayLink slowdown/lag + FIX

[jutah76]

Hi,
I have a setup with 3 monitors (2 27 4k + 1 24 FHD), a Dell UD22 docking station and BetterDisplay to improve the resolution of a 24” FHD monitor. As soon as I launch BetterDisplay, the mouse cursor starts to stutter heavily and becomes very unresponsive.

The mouse is connected via a BT dongle and normally works fine. When I quit BetterDisplay, everything goes back to normal.

Any idea?

[waydabber]

If you have a DisplayLink attached monitor, make sure you disable this, otherwise you'll have lag and the DisplayLink driver/app will produce 100% CPU usage due to a driver issue:

---

UPDATE: Szymon (dev at DisplayLink) confirmed the issue and explained why this is happening. See here: https://www.displaylink.org/forum/showpost.php?p=98997&postcount=3

Alternatively, one has to turn off the "Prevent overlays from affecting screenshots and screen recordings" (see the discussion below) for all displays that use overlay dimming or image adjustments for any reason.

The latest BetterDisplay v4.1.2 version (currently available as internal pre-release) has the offending setting turned off by default, so it should be fine with DisplayLink users.

[jutah76]

thank you this works! but - don't understand why - i see the BD icon and nothing works, i click on it and nothing happens.

i close the app, open it again and. same

[waydabber]

I am not sure why, this might be some other problem - I see your menu icons (including the screen recording macOS icon triggered by DisplayLink) as somehow inactive - so for whatever reason this doesn't seem to be your active menu bar. This is probably an unrelated generic issue (do other menu bar items work)?

[jutah76]

I ran various tests, including disabling the screen-sharing interruption feature you suggested. I wasn’t able to identify a pattern where a specific action consistently leads to BetterDisplay freezing (beachball).

I believe that, unfortunately, users like me who rely on DisplayLink on macOS in order to use multiple monitors together cannot use BetterDisplay.

It seems the two pieces of software are incompatible, both in terms of stability and in the use of BetterDisplay’s core features (for example, HiDPI does not work if a monitor is connected via a DisplayLink docking station such as those from Dell).

This is genuinely unfortunate, because BetterDisplay is a great tool and I truly regret not being able to use it in my setup.

[waydabber]

The issue I am aware of is the DisplayLink app lagging (low screen refresh rate, stuttering mouse and window movements etc) and using 100% CPU when the video overlays are enabled.

Disabling (turning OFF) these settings will also help with this issue:

An other thing that helps (according to many users on the DisplayLink forum) is downgrading the DisplayLink Manager app to v13.x.

The slowdown/freezing issue happens with some other apps as well (mostly those that create a high priority window for overlays or other reasons), not only BetterDisplay.

Regarding features like HiDPI scaling etc, the DisplayLink display is only a virtual framebuffer to the system, fully managed by the DisplayLink app (the DL app then sends over the framebuffer's content in a compressed stream over USB - this is why BetterDisplay can't manage things like resolution etc or establish a direct I2C connection with the display for DDC to work.

All in all, I completely agree that using DisplayLink is not ideal, but a workaround for Mac models that can't handle enough displays natively. But at the same time this might be just fine for most productivity scenarios in an office setting for example.

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ps. BetterDisplay actually freezing might be a completely a different issue which should be investigated separately (except if one encounters this because the DisplayLink driver's 100% CPU usage generally uses up all CPU - then it is not an app issue). When investigating this issue, I tried a setup with multiple displays (one native, two DisplayLink) and things seemed to be working fine (although for me the best solution was to downgrade the DisplayLink driver to a pre-v14 version).

[waydabber]

I posted this issue at DisplayLink's forum, hopefully the devs will respond and we can figure out this issue.

https://displaylink.org/forum/showthread.php?t=69774

There are a number of reports over there about users with similar problems with current DisplayLink drivers (not necessarily BetterDisplay related), so I think the issue will be fixed sooner or later:

https://displaylink.org/forum/showthread.php?t=69768
https://displaylink.org/forum/showthread.php?t=69755
https://displaylink.org/forum/showthread.php?t=69747

Some related threads here:

#3493
#4923 (note: this one ties the issue to BD app version v4.1.1)

[jutah76]

Thank you very much for your interest. I’m not particularly technical, so I struggle to find a solution. As of today, I can say that DisplayLink + BetterDisplay causes strong system instability, even with the option you suggested (monitor sharing disabled).

I’m forced to quit BetterDisplay, and often even that operation is difficult — the beachball appears.

I also have another issue, which I’m not sure is related to DisplayLink. At the moment, BetterDisplay is my only real hope of using a 2K monitor in an acceptable way, but to do so I have to connect the monitor natively to the Mac. There’s no way to get BetterDisplay to work through a Dell docking station certified for DisplayLink.

So, in order to use two 4K monitors, I have to completely bypass the docking station and connect the monitors directly to the MacBook, but this becomes impossible to manage. Is there a solution for this? I’ve tried connecting the monitors to the dock via both DisplayPort and HDMI, but nothing worked.

If I can’t find a solution, I’m afraid I’ll be forced to sell the monitors.

[waydabber]

Are you using mirroring or streaming to get a custom resolution on the DisplayLink display - this is how you are the app? If so, did this work with previous DisplayLink driver and/or BetterDisplay app versions?

[waydabber]

After some additional experimentation, I think this the change that causes the problem:

#4703

If the "Auto detect video call overlays" is enabled in the DisplayLink driver, the "Prevent overlays from affecting screenshots and screen recordings" should be turned off.

I posted some technical info about this at the DisplayLink forum (displaylink.org/forum/showthread.php?t=69774) as this is clearly a DisplayLink driver bug, hopefully devs there will fix this one.

In future app versions I'll have this setting off by default + added a clear comment about this setting does not playing nice with DisplayLink in general:

[jutah76]

First of all, thank you very much for your support.

Today I had the chance to run several tests, and I’m honestly going crazy.

Monitor A: 27” QHD connected directly to the Mac via HDMI.
Monitor B: 27” 4K set to 1920×1080, connected via DisplayPort to the Dell D6000 docking station.

With this setup, DisplayLink (which allows me to connect Monitor B to the Mac) is in total conflict with BetterDisplay.

If I force-quit DisplayLink and disconnect the dock, I can set HiDPI at 1920 on Monitor A. However, as soon as I reconnect the dock and open DisplayLink in order to use Monitor B, the HiDPI setting is lost.

I haven’t found any way to use Monitor A in HiDPI while also using Monitor B.

It’s extremely frustrating.

Do you have any suggestions?

Obviously, if I try to open BetterDisplay while both monitors are connected, BetterDisplay crashes and the beachball appears; the only option is to force-quit it (which takes a long time anyway, as even the task manager freezes).

Thank you very much.

[waydabber]

How are you trying to configure HiDPI with BetterDisplay? The app can't add resolutions to a DisplayLink display as it is managed by the DisplayLink app.

[jutah76]

What I don’t understand is this: I have two setups.

Setup 1
Dell UD22 docking station. Two monitors (one 4K and one QHD) connected to the dock. DisplayLink is active. BetterDisplay works properly. No crashes. The HiDPI monitor is perfectly scaled to 1920 via BetterDisplay.

Setup 2
Dell D6000 docking station. One monitor (the 4K) connected to the dock and one monitor connected directly to the Mac. DisplayLink is active. Crashes and general system instability.

[waydabber]

I see. I am not sure why would Setup 2 experience these issues. Over at DisplayLink forums I see some similar complaints about the D6000 and current DisplayLink drivers.

[jutah76]

Hi Waydabber,

I’m running several tests but I can’t figure out what logic causes BD + DisplayLink to run into problems.

Over the past few days I tested these configurations:

A) 1x 4K display and 1x QHD display connected to a Belkin dock + 1 display connected directly to the MacBook Pro M2 via HDMI
B) 1x 4K display and 1x QHD display connected to a Dell D6000 dock + 1 display connected directly to the MacBook Pro M2 via HDMI
C) 1x 4K display and 1x QHD display both connected to the Dell UD22 dock

So far, the only stable case is C.
Cases A and B work intermittently, with no apparent logic.

The big issue is that when BD crashes/freezes, there’s no other solution than forcing a restart of the Mac. I can still move the mouse, but I can’t perform any action. Only once I managed to kill BD via Terminal, but it didn’t solve anything — the Mac was still unusable, so I had to force a restart.

Do you have an explanation for this?
My hypothesis is that the UD22, thanks to DP Alt Mode, can handle the process better: DP Alt Mode manages the scaling for the QHD display, while the 4K display doesn’t need scaling.

What I can’t explain is why configurations A and B work intermittently, and especially why, when the Mac freezes, the situation becomes so critical that a forced restart is required.

I’m also wondering whether the order in which the apps are launched (DisplayLink first and then BetterDisplay, or vice versa) could have an impact on how things work.

Thanks a lot for the support.

PS: a new version of DisplayLink software has just been released. Maybe this can solve some of of the major crash i'm experiencing.

C Changes in this release

• Support for macOS Night Shift.
• Additional HiDPI modes enabled by default.
• Refreshed GUI and updated icons.
• Fixed issue where one DP-connected screen remained black after upgrading DisplayLink Manager App. (VIFR-6853)
• Enhanced video playback for smoother performance. (VIFR-7115)
• Removed the fake 8K mode from Display Settings when Additional HiDPI modes are enabled. (VIFR-6970, VIFR-7024)
• Resolved mismatch between Display Settings refresh rate and actual monitor refresh rate. (VIFR-6770)
• Fixed DisplayLink App menu bar popping up automatically without user interaction. (VIFR-7107)
• Resolved DisplayLink Manager App crash after running Shortcuts on the app. (VIFR-7110)
• Improved performance when sharing an external screen in Microsoft Teams. (VIFR-7158, PS-5467)
• [DL-6350] Enhanced mouse pointer responsiveness for smoother navigation. (VIFR-7022)

[waydabber]

Let's hope this release improves things. BetterDisplay doesn't do anything special with DisplayLink displays, just treats them as third party managed virtual displays and offers whatever settings are viable for them. I tried a 2-displaylink setup and found no issues, besides the video overlay problem which was explained by the DisplayLink team (see the related forum comment about it) - this should however be an easy fix by toggling the right settings.

[jutah76]

From what I understand, if I keep having problems, the best solution would be to enable mirroring or streaming. Is there a tutorial on how to do it? I’m not very experienced.

[jutah76]

Hi Waydabber,
Quick update: the “stable” scenario C is no longer stable — today I got the same full UI freeze in config C as well.

Environment
• MacBook Pro M2, macOS 26.2
• BetterDisplay: 4.1.1 Build 47018
• DisplayLink Manager: 15.0
• Docks: Belkin F4U095, Dell D6000, Dell UD22
• Displays: 1x 4K + 1x QHD via dock, plus (in A/B) 1 display directly via HDMI

Tested topologies
A) 4K + QHD on Belkin dock + 1 display directly via HDMI
B) 4K + QHD on Dell D6000 + 1 display directly via HDMI
C) 4K + QHD both on Dell UD22

A and B are intermittent. C used to be stable, but not anymore.

Core issue (most important)
When the problem happens, macOS enters a “hard UI stall”:
• mouse pointer still moves
• but I cannot interact with the UI (clicks/menus/app switching don’t work)
• killing BetterDisplay does not recover the system (I managed to do it once, but the Mac was still unusable)
• the only way out is forcing a restart.

This looks more like a WindowServer / display stack deadlock than a simple BetterDisplay crash.

Questions
1. Have you seen cases where BetterDisplay + DisplayLink can trigger a WindowServer stall on macOS (especially with mixed pipelines like dock + direct HDMI)?
2. Is there any known safe launch order (DisplayLink Manager first vs BetterDisplay first) or recommended settings to avoid this?
3. Are there any specific logs you want (sysdiagnose / BetterDisplay logs / DisplayLink logs) to help you identify the root cause?

I’m still trying to isolate the trigger, but it seems related to docking/undocking and/or display reconfiguration events (layout/scaling/HiDPI), because the freeze happens after display topology changes rather than during steady-state use.

[jutah76]

Update. I made these changes:
• I replaced the Dell D6000 dock with another Dell UD22 dock.
• I updated both Dell UD22 docks to the latest firmware.
• I updated DisplayLink to the latest release from two days ago.

Now things seem more stable.

But I still haven’t figured out what triggered that extreme instability on my Mac.

PS: Is there a discount code to purchase BD? Even though I don’t use the advanced features, I’d still like to buy this great software.

[waydabber]

This is good news, thanks for the update about this.

ps. There is a student discount (at https://studentappcentre.com/app/betterdisplay), but aside from that there is no regular discount right now.