Why 5120x1440 Doesn't Work with Apple M1

My Mini M1 was planned for a December 4th to 14th delivery date ... it has shipped from China and will most likely be here (Canada) on November 26th.

From what I gather from reading this thread it clearly does not work out of the box for a 5120x1440. Various suggestions are submitted here but are all too convoluted for my will. I like to keep things simple. Either Apple will support 5120 natively (without a dock or some third party software) (which I doubt is a priority for them) or I will simply double wire the Mini to the monitor (G9) and use it as two 2560x1440 monitors side by side which suits my use case as well and maybe even better. I need to share my screen a lot with Microsoft Teams and sharing a 2560x1440 desktop is way more practical than sharing a ultrawide or sharing individual "applications". (For gaming full screen on the ultrawide I switch to Windows). YMMV.

Please let us know how it works with the dual input (if there are any color issues, brightness issues, motion issues, etc), and if you are using both thunderbolt ports, or one thunderbolt and one HDMI port... like may others, I want this to work...

I will be using 1 HDMI and 1 thunderbolt to DP cable (I only have one TB to DP cable ... and my Windows machine is using the other DP port on my monitor). But yes I will keep everybody posted on the "dual" front.

I have the 2018 Mini and I have the same CRG9 monitor. After upgrading to Big Sur I get 5120x1440 with a single DisplayPort cable (not low resolution). I was going to “upgrade” to an M1 but I’m concerned I won’t get the same resolution.

For everyone who isn't able to get the proper monitor resolution, would you please indicate what cables you are using?

If you are using standard USB-C cables, it isn't going to work.

I did speak with Caldigit who has been working with the M1 devices and Ultrawidescreen monitors and here is their response...

"Thanks for getting back to us. This docking station cannot produce a 5k monitor via DisplayPort on this docking station, but this can be achieved through the Thunderbolt 3 port of this docking station (this is a restriction of the Thunderbolt 3 protocol). Although we haven’t tried this with a 46” Ultra-Wide monitor, we don’t see a clear reason why this wouldn’t work properly."

My thoughts are that any connection to a huge widescreen monitor should include high-speed Thunderbolt 3 -> Display port cable.

That CalDigit guy doesn't know his own product or Thunderbolt.

First of all, 5120x1440 60Hz is less pixels than 4K 60Hz so it requires less bandwidth than 4K 60Hz so DisplayPort 1.2 is sufficient. The Dock supports DisplayPort 1.2, so it is sufficient for 5120x1440 60Hz 10bpc.

HDR is a feature of DisplayPort 1.4 but the bandwidth required is the same (at least 10bpc). I think the CalDigit uses the Alpine Ridge Thunderbolt controller, so its output will be limited to DisplayPort 1.2 so maybe HDR and DSC won't be supported from that Thunderbolt dock. Newer Thunderbolt docks use the Titan Ridge Thunderbolt controller and can support DisplayPort 1.4 features (HBR3, HDR, DSC).

Standard USB-C cables should be fine, as long as they support 10 Gbps USB speeds since DisplayPort 1.2 only requires 5.4 Gbps per lane. Actually - if the display uses the USB-C connection for USB 3.0 ports, then this is not sufficient because the cable will only have two lanes for DisplayPort instead of the require four lanes. Some displays have an option to switch to USB 2.0 over USB-C so that the USB-C cable can have four lanes of DisplayPort. Two lanes of DisplayPort might be sufficient if DSC is supported (requires DisplayPort 1.4) but you probably don't want to rely on that.

For USB-C to DisplayPort cables, I don't think it matters unless you want to try to get 120Hz - then you should make sure they support DisplayPort 1.4 (8.1 Gbps per lane). The cable doesn't include USB so there will be 4 lanes of DisplayPort.

Thanks not only for this information but not killing me, the messenger.

I am only reporting what Caldigit is telling me.

So, let me ask you...

Thunderbolt 3 (4k, 60Hz,40Gbps) -> Caldigit Dock -> Display Port Cable -> 49" Widescreen monitor

Will the new M1 Mini drive it in native 5120x1440 resolution?

It should be able to but I don't have an M1 Mac to test. It seems that they have flaky display handling.

4K 60Hz and 5120x1440 can be done with a Thunderbolt 2 connection (20 Gbps) so even if you had a bad cable it could still work. People in this thread have already shown that 5120x1440 works - adding Thunderbolt devices should not cause a problem.

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

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.

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.

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

Re: changing cables; no, didn't help in my case

Re: DP1.2 vs DP1.4: this shouldn't be necessary and may make M1/Monitor handshaking better BUT it made no difference in my case and then did not allow me to use higher freq nor HDR.

I'm running an M1 Mac Mini to an Acer XV273K 4k@120Hz monitor and I can not get it to work either. It's as if the resolutions supported by the monitor are not being communicated to the system. I can at max select 4k@60Hz and have tried multiple cables which otherwise work just fine from intel Macs to the same monitor. I have also tried disabling Freesync and/or selecting DP 1.2, neither of which had any impact.

I'm currently waiting for the Maxonar cable to arrive from Amazon. I don't see why it would work, but I'm giving it a shot..

Today my M1 Mini arrived. I unplugged my 2018 Mini and plugged the same cables into the M1. It took me over an hour just to get any picture at all!

I have a Samsung 49” ultrawide. 

To fix the issue I set the DisplayPort settings on the monitor to V1.2 and changed the refresh rate to 60. Now I get 5220x1440 on a M1 Mini with 1 DisplayPort cable.