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External monitor support
- Thread starter nowhereman456
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I made a logical conclusion using past experience and knowledge and currently available evidence (Apple's vague specs and the fact that only one display could be connected to Thunderbolt).
Thanks to people's insistence of 5120x2880 capability using subjective visual inspection, we have searched for and found an objective method of determining the output resolution using ioreg. The graphics system on the M1 Macs is totally difference from previous Macs - AGDCDiagnose no longer works and the current version of SwitchResX can't get timing info. Now we have a method to get timing info for the M1 Macs using ioreg. Maybe SwitchResX can use that or maybe there's a new API somewhere.
No-one could have seen that Apple would allow two DisplayPort connections if they are for two tiles of a tiled display but only allow one DisplayPort connection for non-tiled displays - it's a waste of a DisplayPort connection!!! Yet that's what they did.
Here's an idea - can we fake a tiled display with two non-tiled displays of the same size and overriding the EDIDs? Maybe, or maybe not. Previous attempts to get actual tiled displays that are not the usual 5120x2880 have failed (i.e. my 4K 144Hz display has two tiles of 1920x2160 and the Dell UP3218K 8K 60Hz display has two tiles of 3840x4320). Maybe Apple's graphics changes on the M1 have opened up the possibility. Here is a test with the HP Z27q 5K tiled display : https://egpu.io/forums/desktop-comp...thunderbolt-4-usb4-pcie-4/paged/4/#post-89687
Amazon Fire Stick + Airplay mirror Receiver comes cheaper than Apple TV for that usage.
It’s pretty frustrating. Out of all the hard work they did on these new systems; this is the one part that feels rushed. I think they could have done better.
I thought about trying to figure out how to get my two 1440p displays to look like a single dual wide display using a matrix controller or something, but in the end I just went the Displaylink route. It’s honestly working pretty darn well, and I can even add a third display if I want (for 4 total if you count the internal display).
Ok,reading your setup from earlier in the thread, I gather I would just need the Apple adapter to add to my HP G2 dock to get a dual monitor setup to work?
Apple Adapter out of MBA.
HDMI connection to one monitor via Adapter.
G2 dock via USBC into the Adapter. 2nd monitor would go into the DisplayPort on that dock.
And I would have the use of the other various ports on the G2 dock, and that will provide power to the MBA as well, correct?
What isn’t clear is would I have a 3rd (using the 2nd DisplayPort on the G2 dock) external display potential too with this setup?
Nope, nobody said you can do dual monitor with a Thundebolt dock.
You need a DisplayLink hub or AirPlay for the second monitor.
Thats me on reddit. It is working now without any extra program via clicking scaled by holding the option key. Sometimes my mbp forgets the settings on runs again on 3840x1080. Also the fonts size is super small and hard to read. I hope there will be a patch
DisplayLink is a 5 Gbps USB device. Video is normally much greater than that. There is a lot of compression. The CPU has to do some work to do the compression. It's not good for video or gaming but is ok for normal productivity stuff (browsing, e-mail, text editing, etc.)
There are some YouTube videos showing DisplayLink on the M1. It seems ok even when moving windows around.
My guess is that through their market research, they know that most buyers of these 3 models use only one display (i.e. the internal display in the MacBooks and a single monitor for the mini), or 2. However, given the extremely good CPU and GPU performance, a lot of "pros" are interested. I wouldn't be surprised to see an updated higher end MacBook Pro in Q2-2021 (perhaps the rumored 14"), so as tempting as the M1 MacBook Air/Pro may be, those who really do need 2 or more external displays should probably hold off a few more months.
I worked today with my native connected 1440p display on the left and the Displaylink 1440p display on the right. It was difficult to notice any difference between the two unless I played back video in a large window on the right. Then it was obviously running at a low frame rate. It's sharp and clear and the colors look good, but high frame-rate is not possible. I guess an analogy would be like if it was a 20hz (20fps) display.
I did not notice any kind of pixelation or compression artifacts though.
Apple definitely is not used to someone having multiple monitors. I've had issues with two LG Ultrafines attached to my old Pro and never could get Apple to fix it. Everyone I spoke with was stumped with how they could even find two monitors to test with.
This is especially ironic because Apple invented the concept. My 1987 Macintosh II was capable of using up to 6 displays if you installed 6 NuBus graphics cards. Talk about being ahead of its time!
Anyway, multiple displays for creative professionals was possible from the earliest days of the Mac (even before the Mac II you could install graphics cards in certain Macs).
I don't know what Apple was thinking if they weren't testing for multiple screen setups even on their base models. It's understandable they chose to not support it, but being confused about it is just rediculous.
By any chance, could you post a pic/screenshot of how small the text size is to give us an idea? Is it to the extent that it is unusable?
Thanks!
I just ordered a TB3 to dual DP adapter so can probably test it with the UP3218K some time next week. That looks promising.
You mean a TB3 to Dual DisplayPort 1.4 adapter? Without DSC, 8K 60Hz is too much bandwidth for a single Thunderbolt 3 port (6K is the max in that case at ~36 Gbps). I've never seen dual HBR3 work with anything other than the XDR display. If you used the TB3 to dual DP1.4 adapter on a Mac that supports two displays, then you would probably be limited to dual HBR2 or HBR3+HBR.
One question I have is, can the DisplayPort mux that moves the DisplayPort connections from one bus/port of an M1 Mac to the other bus/port connect one signal on the first port and connect another signal on the other port and still allow a tiled display like the Dell UP2715K to work? If that works, then that is the method I would use with a Dell UP3218K since you won't be limited by the Thunderbolt cable.
I did compare Display Override files between Big Sur release and Catalina and there was no change with the Dell UP3218K override file - so that might still need to be modified (and an .mtdd file added). I haven't tried creating an .mtdd file in Big Sur - someone said putting an .mtdd file in the /Library display overrides path doesn't work - it needs to be in the /System/Library display overrides path - so that will need to be tested. Who knows if M1 Macs even use the display overrides still? There was a log with displaypolicyd but I don't know if that's used on M1 Macs #41
But left out a bit of common sense and knowledge of Apple's past behavior. The rules are clearly different for their own products.
Anyway, no harm and it's good news that the 5K display works.
Honestly, the bigger question is: given the craptastic landscape of prosumer displays (just try to find a feature-equivalent display to the UltraFine 5K that isn't as unreliable as it is), why hasn't Apple fixed the problem with an updated Thunderbolt Display? I would order a couple TODAY if they announced it.
- Mark
I've made a short video for u. It is hard to capture the "feeling". Usually, I have been using the monitor with my windows pc over dp1.4 5120x1440 (RGB). With the mbpm1 it is 5120x1440 (ycrcb444). I don't know if this is normal under macOS...! In apps where I can't resize the font, it is hard to read and I have to move forward to see it. Here is the video
5120x1440mbpm1.mov
drive.google.com
Yeah, just hoping for 10-bit 30Hz.
Although isn’t it just two tiles of 10-bit 3860x2160@60Hz (17.92Gpbs) each?
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You forgot to double the height.
8K 30Hz 8bpc is doable with a single tile HBR3 connection.
8K 60Hz 8bpc is the max with two tiles HBR3 3840x4320
The UP3218K does not support DSC. Does it support 10 bpc? The specs and EDIDs say yes (1.07 billion colors = 2^30).
For 10bpc, the options are:
8K 24Hz single cable.
8K 48Hz dual cable.
Intel Macs that support DisplayPort 1.4 can do the single cable options already (you have to override the EDID - remove Apple's override - to restore the 8K options).
My Ultrafine 4K works fine. How can I tell if it is in 8bit or 10 bit mode on Big Sur? used the system report before but it no longer mentions color depth.
I have a Dell WD19TB at work, gonna test my M1 MBA with it on Monday and dual screens via Thunderbolt as the Dell support document suggests. I wasn't aware of the single external monitor only when I ordered it on launch day. It is just ridiculous, my 12" Macbook has the Anti reflective coating issue, I'm gonna let that get fixed and return my MBA afterwards if no solution like DisplayPort MST is available. As great as this machine is (it feels phenomenal), this is such a *profound* flaw...I don't know what to say...I'm working fo a research institute everybody uses 2 or even 3 screens.
Ok, so for there with the same issue as my (see my previous post), last two days, after setting everything up, I've been consistantly getting the 5120x1440 to work as follows:
1. Open lid
2. Plug in monitor (external power not plugged in)
3. The monitor starts working in amount 15-20 seconds,
4. Plug power in
5. Close lid
If the computer goes to sleep, I still can't wake up the external monitor and have to repeat the script above. Although a pain in the neck, at least I am happy the drivers are there and it's just a bug. Hopefully they will work it out soon.
1. Open lid
2. Plug in monitor (external power not plugged in)
3. The monitor starts working in amount 15-20 seconds,
4. Plug power in
5. Close lid
If the computer goes to sleep, I still can't wake up the external monitor and have to repeat the script above. Although a pain in the neck, at least I am happy the drivers are there and it's just a bug. Hopefully they will work it out soon.