Yes they are. Two 4 lanes encoded into thunderbolt stream i.e 8 lanes of display port traffic on the link. I didn’t say they are all 8 lanes going to the same sink. The display has two sinks and traffic from both of them a total of 8 lanes is tunnelthrough thunderbolt.
The LG UltraFine 5K display is connected exactly the same as a dual cable display connected to a Thunderbolt 3 to dual DisplayPort adapter. In either case, the two DisplayPort connections are tunnelled through Thunderbolt.
I don’t see why Apple would restrict things to one display if there were more resources to support more displays like the Intel or AMD GPUs.
The M1 doesn’t support 3 displays so ergo it it doing some thing to share one display resowith tiled displays.
Right. The M1 has two DisplayPort connections for Thunderbolt, but some restriction makes Apple allow only one display, either single or dual tile display.
How apple handled things in the past doesn’t really matter.
It kind of does. In the past it worked. A user of past machines expects it to continue working for the present machine. It works, but only after you do a magic dance.
For M1 Macs? I couldn’t find it in the support documents.
I said wayback machine. It's a website that archives webpages. The pages I refer to predate the M1 Macs.
Here's the old page from Nov 23, 2019:
Learn about Mac support for 4K displays, 5K displays, and Ultra HD TVs. Also learn about the system requirements and how to set up and adjust the display or TV.
web.archive.org
This page mentions dual link SST (which is what LG UltraFine 5K and the dual cable displays are):
support.apple.com
Yes on intel Macs. We are not talking about intel Macs.
We are talking about tiled displays. It is the nature of tiled displays that the order of connection and the timing of connection is not deterministic. Apple cannot depend on connection order or connection timing to support tiled displays, whether the display has a built-in Thunderbolt controller like the LG UltraFine 5K, or uses an external Thunderbolt controller like the Dell UP2715K or HP Z27q connected to a Thunderbolt 3 dock or a Thunderbolt 3 to Dual DisplayPort adapter.
Not if Apple never claimed to support two cable tiled displays. I’d like to see the support document that says M1 Macs support two displays or two cable tiled displays. Also it has nothing to do with graphics, the display engine on all GPUs/SoC is different blocks on silicon. The M1 SoC has 7-8 core GPUs vs 4 on iPhone. I have no idea what Mac graphics means in this context when it clearly outclasses most integrated GPUs on Macs or even PCs.
All M1 Macs support two displays. I think you mean M1 Macs don't support two displays from Thunderbolt - we agree on that.
I think the Apple Store page is the only page that says the M1 Macs are compatible with the LG UltraFine 5K display. It doesn't say if the display support 4K or 5K in that case. Apple usually doesn't mention compatibility about third party displays, except in that past support article, and except for the LG displays that it sells. Usually displays that are similar should have similar compatibility (they follow the same standards and specifications - DisplayPort, EDID, etc; the purpose of such standards is to allow compatibility). The Dell and HP displays, when connected through a Thunderbolt 3 dock or adapter, are similar to the LG UltraFine 5K and therefore work as the LG UltraFine 5K does (but may require jumping through some hoops).
Mac graphics means all the software that Macs used to handle displays.
- CoreDisplay, AGDC, IOGraphicsDevice:IOFramebuffer, IODisplay:AppleDisplay, ?
iPhone graphics means all the software+hardware that iOS devices use to handle displays.
- IOMobileFramebuffer:IOMobileFramebufferService:IOMobileFramebufferAP:UnifiedPipeline2:AppleCLCD2 ?
