Big Sur 11.1 - 30hz External Monitor on 2019 MacBook Pro

Sorry for the late reply. It's fixed by going to the monitor's setting for now.

System > Advanced > DisplayPort > and Change from 1.4 to 1.2

Sometimes, you have to unplug and plug the TB3 or change to other ports again.

I also have and test with the MBP 13" M1. it works. Hope this helps.

I have a BENQ PD3220U using DisplayPort connection to usb c on MBP16 on 11.2 Big Sur

1. I changed DPort settings to 1.2 from 1.4
2. Got into advanced mode on Display setting by holding ALT and clicking scaled https://youtu.be/-epAJtrPmLE?t=113
3. Click manual low resolution
4. then click 60Hz

Worked for me, hopefully for you too.

We have also seen cases recently where a DisplayPort display worked fine at 60 Hz when its internal spec was set for DisplayPort 1.2, but when its internal display settings (in the display itself) were changed to DisplayPort 1.4 (which allows data compression) the display dropped back to supporting only 30 Hz refresh rate.

My guess is that it could not quite keep up with the higher resolution AND data decompression required by DisplayPort 1.4. This will vary on a model-by model basis.

Thank you so much, I had this problem for months now, always restarting 5-10 times to get my Benq PDQ2720U working properly at 60Hz.

This fixed it for me!!

"System > Advanced > DisplayPort > and Change from 1.4 to 1.2"

Thank you so much, I had this problem for months now, always restarting 5-10 times to get my Benq PDQ2720U working properly at 60Hz.

This fixed it for me!!

"System > Advanced > DisplayPort > and Change from 1.4 to 1.2"

One other suggestion users have made: actively change the resolution settings.

Change the resolution to something less demanding, save changes and close the window.

Then change the resolution to the one you would like to live with long-term, save changes and close the window.

At least one Reader reported that this 'act of making a change' fixed their display performance problems.

You probably have an old HDMI adapter (if you connect via HDMI), or your adappter doesn't support 60Hz.

http://forum.notebookreview.com/threads/macbook-pro-16-very-slow-performance-with-oled-tv-55.834999/

I don't think readers here have any tips for that. You will need to contact support (there is a link at the top of every web page) and press on until they file a Bug Report.

Do not let them say this is fine and drop the issue, or it will never get fixed for you or for anyone else.

To help yourself and everyone, you need to use the 'Contact Support' link and tell Apple support about this.

Do not relent until they file Bug reports for BOTH these problems.

Otherwise, Apple does not 'know about the problem', and is Not 'working on a fix'.

Indeed, but was wondering if it's an Apple acknowledged issue also for the new M1 set of devices. But since also the Intel-based devices have issues as the MBPro16, I hope an update of BigSur will fix all cases (so far 11.2 beta is reported not to fix it yet, unfortunately).

Yes, direct Connectivity through TB port without any adapter is a known Bug for latest BigSur update and MacBook Pro 16

Indeed. Big Sur 11.2 did NOT fix the lack of 60Hz via TB3 display connection.

Jan, thank you for these suggestions, appreciated!

Unfortunately, non worked for my bend pd2720u + macMiniM1 via TB3 (or DP via TB->DP adapter).

I've downgraded DP version in the monitor repeatedly to 1.2 or even 1.1 but no good result.

Then:

• Left DP on 1.2,
• shut down, boot,
• change resolution to the only resolution that allows 60Hz, 1280x720 (the monitor menu and also system information both declared Resolution 2560x1440 with UI looks like 1280x720@60Hz)
• closed all windows
• restarted display settings and switched to scaling 1080
• screen went blank (normal, since refresh rate and native resolution changed)
• check monitor menu and also system information again and they show 3840x2160 with UI 1920x1080@30Hz.

Completely ran out of ideas :(

step1

step2, 60Hz is simply not available above 720p

i had the same problem.

my T3 simply showed "no signal" + black external screen.

i now work with a SATECHI hub (usb-c > HDMI) to connect the screen via HDMI,

the results are this (seems that I am on 30hz too)

i am utterly UTTERLY disgusted.

11.2.3 / Macbook Pro 16" 2019.