Why 5120x1440 Doesn't Work with Apple M1

Hey all, my setup has the Samsung G9 with the M1 Mac Mini, and a desktop PC with an RTX2070. Watching some youtube vids, i made sure to buy a direct DisplayPort to USB-C cable that supported 1.4. I thought that would solve the issue, however, i still had to do some tinkering, although i think you'll still need a direct cable with DP 1.4 support for this to work.

Before playing around with the settings on the computers and the monitor, switching around and wake from sleep bugging out on the Mac Mini was really annoying. Even with the 1.4 direct DP > USB-C cable.

However, I think i've landed at a config that works, although this still requires the use of SwitchResX. Hopefully this will help some of you, there's a trial so you can try anyway.

G9 Monitor Settings:

Game: Refresh Rate > 120hz (240hz would bug out on wake from Mac)

Game: Adaptive Sync > off

System: DisplayPort Version > 1.4

Driver Version: 1008 (get from samsung site, requires a usb stick)

Mac Mini:

• Used SwitchResX to set the display to 5k 120hz.
• Setting Monitor to 240hz seems to bug out when i switch from PC > Mac, setting it to 120hz seems to not have this problem.

Mac OS: Big Sur 11.0.1

So my final judgment.

I am keeping the Mini M1 ...I am returning the MacBook Pro M1 (I was to keep one of the 2)

My monitor is the Samsung Odyssey G9 (5120x1440)

I need a Caldigit TS3 for my use case.

The mini has flaws/bug but none are visible anymore if I use the TS3.

MacBook is excluded on the simple fact that it supports only one external monitor (otherwise it was as good as Mini).

Bugs / annoyances

• MX master mouse skips when on Bluetooth ...solved my using Logitech dongle (and possible because of extra USB ports offered by TS3). Dongle is plugged in Mini directly.
• Display port won't wake up ... solved when using TS3 (but there is clearly a problem with mini there on diplayport)
• Small pink dots on HDMI monitor... still there but rare and only lasts a couple of seconds.
• Mini does not offer enough ports... solved with TS3.
• Mini does not detect full resolution and refresh rate ... solved with SwitchResX
• Home Office Headset does not work well in Bluetooth .. solved by plugging Jabra base though USB (headset remains wireless)
• Dual monitor mode ( picture by picture / dual cable) . Works (one DisplayPort cable going to TS3, one HDMI cable going to mini). This is my main daily use mode.
• Ultrawide mode (5120x1440 @ 120Hz) works, display port through TS3, + switchresx + unplug the HDMI cable (otherwise i get phantom monitor). I dont need ultra wide when using mac... so no big deal here... I use the ultra wide with Windows through the other DisplayPort.

Essentially in the morning I walk to the mac ... tap the keyboard which wakes and unlocks the mac with Apple Watch.. then start using my picture by picture monitors for work. No fiddling. Left side Citrix.. right side Office 365.

As for the MacBook if I had chosen to keep it I would have had to let go of my picture by picture mode and I just can't.

For gaming I switch to my PC and use the same monitor 5120x1440 @ 240Mz with Gsync. All good.

I'm sharing this in the hope it helps a lot of people. After hours of trying to work this out and starting a return for my M1 MacBook Air, I've got a solution. I'm using a 49 inch super ultra wide monitor and simply couldn't get it to work at all, not even acknowledge a monitor is even plugged in, it works absolutely fine on my 16 inch 2019 MacBook Pro. The solution after hours and hours was to switch the setting on my monitor down to Display Port version 1.2 from 1.4, once I did this I could finally get an image albeit not at native resolution for the monitor. Once in Display Port version 1.2 at least with a low resolution image (I was getting nothing before), I could then use SwitchResX and FINALLY it would see the monitor so I could increase the resolution up to 5120X1440 @ 120hz, and all is FINALLY working fine. What a serious mess, and wasted days trying to get the M1 to even acknowledge a 49 inch monitor but finally this is a solution that works.

Please don't ask why, I still don't know but at least it's a solution. Possibly something to do with Freesync on the monitor, maybe the cable? Clearly it's something though with the M1 as my other Macs all pick up the monitor automatically all using the same cables and the monitor on display port version 1.4, anyway switching it down to 1.2 then using SwitchResX has solved it.

What do I win? lol

I don't think this is a real problem, the repo owner put this message to clear himself of any responsibility.

By default, only with the Apple settings it is possible to activate 5120x1440 120Hz with the following procedure, but just after disconnecting from the screen or rebooting the setting is not kept, the GitHub repo just allows to go faster. So I think this is not a hardware constraint, but just an optimization problem. After all it worked fine with an Intel 2020 MacBook Air.

To succeed without software just disable the FreeSync, hold the option key and select 5120x1440 and then in the screen settings change from 60hz to 120hz. Select 120 in the input "Refresh Rate" You will see that the resolution of 5120x1440 is kept and the frequency is 120hz. (in the setting the resolution of 5120x1440 will not be displayed in the list).

MSAGA146,

I have the same exact monitor and it's working beautifully with the M1 Mini.

You need to be on Big Sur 11.2. Not sure if it is out of public beta or not. I think it was just released.

THEN you can get the resolution you are looking for. If not, you can do so with the help of SwitchResX software.

I have no issues with waking up the monitor. There was a one-time issue where I woke up the monitor and there were all these color distortions. I just rebooted the M1 Mini and it was fine. Only happened once. Otherwise, having much success here.

A USB-C to DisplayPort cable is just a cable - it does not fix problems with the source. It can do 8K only if the source supports 8K. Maybe the USB-C ports of an M1 Mac have voltage or signal problems or don't read the e-marker chip of some cables properly or something like that. Putting a Thunderbolt dock between the M1 Mac and a display can clean up the signal. An M1 Mac that can't get out a proper DisplayPort signal may be able to get out a Thunderbolt signal. A Thunderbolt dock takes Thunderbolt data from the M1 Mac and recreates a DisplayPort signal from that.

I have the same Samsung C49RG9x display and the new base M1 MacBook Air.

Using this adapter - https://www.amazon.com/gp/product/B07F17ZHJY/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

I also had to set the monitor setting to FreeSync OFF, 60hz; but could only set the 5120x1440 resolution using SwitchResX.

One other note I have is that 120hz refresh rate was possible @ 3840x1080 with EasyRes.

5120x1440 @ 120hz is still not possible with the combinations I've tried.

@NJ Ron, sorry, I forgot that you had already stated your connection configuration. The Caldigit dock is acting as a TB3 to DP converter. I believe it is DP 1.2. I have seen other suggestions that setting your monitor DP level to 1.2 can help, although it made no difference to me. I have installed ScreenResX to help see what the CRG90 and M1 negotiate as possible resolutions/frequencies and to select some that the M1 does not present in Display properties.

I can confirm that I KNOW and have had the M1 Mac mini successfully display 5120 x 1440 @120hz SDR with my CRG90 using a USB-C to DispalyPort cable (2 different cables). But the M1 and CRG90 do not negotiate a connection properly or with consistently and for me usually presents with a blank screen, no backlight, no rear lighting.

The most consistent way I have had the CRG90 work with the M1 is to have another monitor hooked up to HDMI (or the CRG90 itself) and when it detects the CRG90 over DP as an extended desktop screen, increase the resolution on the HDMI monitor and then unplug the HDMI and the CRG90 remains as my primary screen until I reboot (it worked while waking from sleep). This approach/work around worked for me a number of times.

I can NOT say the two won't work. I can say it is buggy at best. It has worked flawlessly on HDMI at 3840x1080 @100hz HDR

I am having a new adaptor delivered that others have reported better success with and will try, again, the DP1.2 setting on the CRG90 to see if I can get better consistency.

Opps, hit send to fast:

I can confirm the M1 can display 5120 x 1440 @120hz SDR.

But the handshaking between the BigSur OS, M1 and Monitor over DP is flakey and the majority of the time it fails... and then you have to force a re-handshaking by unplugging/replugging the monitor in.

Sometimes it works and the OS lets you pick the resolution (with a Opt + click), sometimes it is only recognized with a constrained resolution or HDR missing or limited to 60hz. In most cases, not sure why, the OS is aware of all capable resolutions even if it doesn't provide them through the OS interface, so if you use a third party tool for setting the resolution it also can work (5120 x 1440).

Does it work? Not perfectly right now, its buggy at best, but the capability is there.

Update:

I hope everyone had a happy and healthy thanksgiving.

I have m1-MM 8gb/1tb connected to Samsung CRG9 49” monitor via usb-c to DP port with the maxonar cable (usb-c to dp1.4). With freestyle off and monitor set to 60Hz , it’s working at full res (5120x1440). (These Samsung monitor settings were crucial to making this system work)

Initially, I too still had issues with the connection being unstable after awakening from sleep requiring me to remove and reinsert the cable into the back of my m1-MM, but this has not happened in the last day! (My next step was to download ScreenResX software, but for the moment, I have native working system without hardware or software workarounds!)

I have had my mini for just over 48h but I will keep you updated; and thank you for these suggestions that seems to, at the moment, be working. Let’s hope I’m not counting chicks too early...

Right now I'm using Mini M1 with one Cable Matters TB to DP 8k cable and Samsung Odyssey G9. 5120x144 @120Hz set with SwitchResX. No visible problem yet. Not tested the wake from sleep which did not work perfectly with my previous setup.

Also I have switch my MX Master mouse to the Native bluetooth (no dongle) and it works fine if I don't also connect my Jabra Evolve 75 through bluetooth. So the Jabra uses a USB port. If I set the Jabra on bluetooth the mouse starts to skip. So right now on bluetooth I have MX master and Apple Keyboard.

So I guess if your are willing to add SwitchResX to the mix (and maybe suffer some not so elegant wake from sleep) you can absolutly use the mini M1 with a 5120x1440 Ultrawide (with a good TB to DP cable).

I finally have a real simple and effective solution!

I have a samsung 49" 5120x1440 120Hz screen with FreeSync with my MacBook Pro M1

The macbook is fully capable of running this resolution and 120Hz refresh rate.

you just need to install a small app available here: https://github.com/Eun/DisableMonitor with a displayport 1.4 cable

Look at my screenshot

Just received my Mini M1 16GB/1TB today and can confirm that with the Cable Matters cable/adapter combo that I posted on page 1, and here again for reference: https://www.amazon.com/Cable-Matters-DisplayPort-Resolution-Support/dp/B08C9NPC2S everything works perfectly.

It booted up and recognized my AOC AGON 49" Ultrawide's 5120x1440 native resolution but at 60hz. I simply went into display settings and selected 120hz which was available without any special keypresses or other software.

So for anyone looking for an Ultrawide that works at its advertised specs, take a look at the AOC along with the cable/adapter combo that I linked above.

Good luck everyone, this new Mac is a treat so far!

I use the M1 MacMini with a Dell U4919DW curved monitor with native 5120x1440 resolution with a direct connection via the original USB-C cable from the monitor supplied accessories. The M1 MacMini I received today is running BigSur 11.0.1 and worked at once with the right setting and auto negotiation. So the resolution seems not the issue.

Maybe the resolution Frequency combination is a hurdle for the Samsung on the HDMI since the Monitor offers 120Hz as far as I know.

I also have a Samsung Odyssey CRG9 49 curved Monitor and can confirm, that this monitor refuses to offer the full resolution over HDMI and falls back to 3840x1080. I did not test any Display-Port cables. It is either a limitation of the HDMI/Cable combination or the EIDE Firmware in the Samsung that offers the wrong data or the M1 is not able to negotiate well.

The Samsung offers by default only 3840x1080 60hz on a Gigabyte BRIX Windows 8.1 machine with a dedicated Geforce GTX760 . It can then be forced without special tools to use the full 5120x1440 with 30Hz in the System Configuration (marked as not recommended).

I did not try the "Alt-Click" on "Scaled" method in the M1 MacMini "Resolution Settings" for the Samsung yet.