Why 5120x1440 Doesn't Work with Apple M1

Did you change the settings on your screen? This cable worked for my samsung super ultrawide monitor. I still sometimes have to remove and replug the cable though

For me it is working see my screenshots above.

I had to replug it once tho, so that my Mac mini finds it, Isn't your screen detected at all or dent it just show the fill resolution ?

As for myself with the mini M1, after using it couple of days, I can work around most the issues but there are quite a few issues. I connected my Samsung G9 in PBP mode (2x 2560x1440... one DP and one HDMI). The DisplayPort side does not always wake up from sleep. The HDMI side is always there but sometimes has green or pink dots that show on the display. Bluetooth is not stable enough to drive mouse so I need to use a USB port for Logitech dongle. It adds up.

Otherwise during use all is fine.

All this tells me something is not quite ready. So I ordered a MacBook Air M1 and a Caldigit TS3 to do some more testing and I will keep on ordering and returning until it's right. The performance is so amazing that I had to rethink the Laptop vs desktop thing ... I don't feel I would be penalized if using a laptop as my work from home setup and so I would also get portability with MacBook for whenever we get our normal world back. Also with the Mini I have already maxed out all the ports so I will need the thunderbolt Dock anyways... so once I have buy a TB dock the MacBook suddenly becomes an option for me.

me wants apple silicon... without bugs

So far it does work for me at least somewhat. I can run it in full 120Hz without any issues to wakeup wit DP 1.2 but no joy with DP 1.4 neither in 120Hz or 60Hz. Tried SwitchresX Beta where I had to disable System protection (and I rather don't wanna do it) but also no change. DP 1.4 is just not working so far.

Also with System Protection disabled I cannot run iOS Apps where I rely on some Apps which aren't working for the M1 Processor yet.

That's fair, personally i think this is not really a hardware-blocked issue, since it does work (with somewhat convoluted steps). I think if Apple is made aware, and enough people encounter this, a software/firmware fix should be quite realistic without having to wait for an upcoming generation of new hardware.

Same dramatic situation here. I own a Macbook Air M1 and a LG 49WL95C-W (5120x1440@60Hz). They are connected using USB-C cable (1.4 version) and the monitors can take the native resolution (it works at 3840x1080@60Hz).

Furthermore, it has a crazy behavior:

• if I close the lid, often the external display power off and I cannot wake it up anymore (the only way is a whole rebooting).
• if the Macbook goes in Standby mode, the external display power off and I cannot wake it up anymore (the only way is a whole rebooting).
• if I disconnect the cable, then I try to reconnect it, it doesn't wake up anymore.
• Sometimes, it lose the HDR flag in the Monitor settings.

I own a Macbook Pro 16" Intel based as well and they work fine together.

Please, Apple do something!!!

When I had to select initially the resolution, the option shown was only "5120x1440 (low resolution)". When i checked later on, it was showing just "5120x1440". I just checked again now and "5120x1440" disappears from the list, as soon as I access the "Display" windows, from System Preferences. It literally disappears 0.1sec after opening the Display window... Very strange. Good thing though is that the resolution is not affected and keeps on working at 5120x1440.

I did 3 months of research on what system to buy (build) that can support stacking 2x49" C49RG at 5120x1440 and had my finger on the trigger to purchase a windows PC AND the M1 mini just hit the market. I was impressed with the power consumption and looked at the spec. I couldn't believe it said 2 x 5120 support. I open a chat to confirm and I asked the rep at least 3 times and said I don't believe it and s/he himself was amused that I couldn't believe it. I was assured it supports it and we are talking APPLE company. Their products go through extensive quality assurance and I was sold with the marketing. 

I ordered the 16gig 8gpu. I can't even get 1 C49RG to work. It took me 3 days just to research, buy a new cable and hold the option button down and do this and that and finally got it to come up, BUT now I have to disconnect the cable and re-connect it 2 times for the screen to wake up. 

The mini has crashed on me 2ice. *CRASH*. when did you ever hear a mac “blue screen”!? System preferences unexpectedly crashed on me. (I have screen shots) I use Visual Code for work. It crashes on me. This morning it had rebooted on me and all my apps were moved around. I don't have auto-update enabled. I tested Java on my wife's M1 laptop and it worked. But now that I use it more the memory usage all of a sudden jumps 1gig every 3 seconds and I have to kill the process with mem usage 25+ gig. 

I am disappointed. if you want a mini (M1) to just browse the web and iMessages, then go for it. M1 release is premature. not happy!  Oh not to mention my bluetooth devices connect and disconnect. My headphone & Logitech Craft keyboard doesn’t even connect. I am calling BS on Mr Cook!

Strange thing. Quickly ordered the CableMatters DP Cable from Amazon. Switched to DP 1.4 and it worked (even after a reboot) but it raised a new issue. Since I used the Cable my monitor will display the connected port in the OSD every 5 seconds. Very annoying so I used my original cable. Well I expected that I have to use DP 1.2 again but no it still works. The whole DP thing ist still somewhat wonky. Dunno if it is due to the fact that I updated to 11.3

I have a 2018 mini and with a single cable I get 5120x1440. I didn’t until I installed Big Sur.

Have you seen the screenshots on Page 2? Others are getting 5120x1440 (not low resolution) on an M1

Although I get 5120x1440 with my M1, when the machine wakes from sleep 50% of the time it wakes in a lower resolution and I have to manually select it again. My 2018 Mini doesn’t have this problem.

fyi changed to DisplayPort 1.2; had to go to 1.1 then 1.2...will keep you updated.

I don’t know game either. I have the Samsung G9 and I run it with a DP cable from my Mini M1 in 5120x1440x60hz without SwitchResX

95% of the time I have no issues and it wakes and sleeps fine.

You need to change 1.4 to 1.2 in settings.

Go back to DP1.4 and you should get FreeSync now as well.